【写真特集】錦織圭～世界に誇る日本テニス界の至宝～

Japan’s Kei Nishikori celebrates after his victory against Brazil's Thiago Monteiro in their men's singles match on day one of the Australian Open tennis tournament in Melbourne on January 12, 2025. (c)Yuichi YAMAZAKI / AFP

Japanese Davis Cup team players (L-R), Kei Nishikori , Go Soeda, captain Eiji Takeuchi, Takao Suzuki and Satoshi Iwabuchi , pose for a photograph in New Delhi on April 9, 2008. India are looking to put aside their internal squabbles as they prepare for Friday's Davis Cup tie against Japan that will lift the winner into the world group play-offs. India and Japan are scheduled to play in the second round of Asia/Oceania Zone Group I match in the Indian capital from April 11-13. (c)MANAN VATSYAYANA / AFP

Japan's Kei Nishikori returns a shot from Spanish Rafael Nadal during the third day of the Artois Tennis Championships on June 12, 2008 at Queens lawn tennis club, in London. Nadal won 6-4, 3-6, 6-3. (c)CARL DE SOUZA / AFP

Kei Nishikori of Japan receives treatment from a trainer as he plays against Marc Gicquel of France during their first round match of the 2008 Wimbledon Championships at The All England Tennis Club in south-west London, on June 23, 2008. (c)ADRIAN DENNIS / AFP

Japan's Kei Nishikori returns the ball to Germany's Rainer Schuettler during their men's singles first round tennis match for the 2008 Beijing Olympic Games at the Olympic Green tennis centre on August 11, 2008. (c)BEHROUZ MEHRI / AFP

Japan's Kei Nishikori hits a return against Guilermo Garcia-Lopez of Spain during their men's singles second round match of the Japan Open tennis tournament in Tokyo, on October 1, 2008. Nishikori won 6-4, 6-4. (c)TOSHIFUMI KITAMURA / AFP

Japan's Kei Nishikori returns a ball to Spain's Marcel Granollers on the 1st day of the Stockholm Open Tennis tournament on October 6, 2008. (c)OLIVIER MORIN / AFP

Kei Nishikori of Japan (R) receives treatment on his injured arm in his match against Paul-Henri Mathieu of France in the quarter-finals of the Brisbane International being played in Brisbane, on January 8, 2009. The tournament is used by top players as a warm-up for the Australia Open starting January 19, 2009. (c)WILLIAM WEST / AFP

NEW YORK - FEBRUARY 14: Athlete Kei Nishikori attends the Y-3 Autumn/Winter 2010 Fashion Show during Mercedes-Benz Fashion Week at the Park Avenue Armory on February 14, 2010 in New York City. (c)Andrew H. Walker/Getty Images for IMG/AFP

Japan's Kei Nishikori reacts after he defeated Colombia's Santiago Giraldo during the men's first round match in the French Open tennis championship at the Roland Garros stadium, on May 24, 2010, in Paris. The event, the second Grand Slam tournament of 2010, runs from May 23 to June 6, 2010. (c)CYRILLE CADET / AFP

Japan's Kei Nishikori returns a ball to Spanish player Rafael Nadal during the Wimbledon Tennis Championships at the All England Tennis Club, in southwest London, on June 22, 2010. (c)IAN KINGTON / AFP

Spain's Rafael Nadal (L) shakes hands with Japan's Kei Nishikori (R) during a press conference for the Japan Open tennis championship in Tokyo, on October 4, 2010. (c)TOSHIFUMI KITAMURA / AFP

Japanese tennis player Kei Nishikori smiles after winning against his Croatian opponent Marin Cilic, during their first round match at the ATP Chennai Open 2011, in Chennai on January 3, 2011. Nishikori won the match against the defending champion and second seed of the tournament Cilic 4-6,7-6,6-2. (c)DIBYANGSHU SARKAR / AFP

Kei Nishikori of Japan returns against Fabio Fognini of Italy on the first day at the Australian Open tennis tournament in Melbourne on January 17, 2011. Nishikori leads 2 sets to 1 as the match continues. (c)PAUL CROCK / AFP

KEY BISCAYNE, FL - MARCH 25: (L-R) Kimiko Date-Krumm of Japan, Kim Clijsters of Belgium, Kei Nishikori of Japan and Ayumi Morita of Japan pose for a photo as part of "Tennis Family for Japan Relief" during the Sony Ericsson Open at Crandon Park Tennis Center on March 25, 2011 in Key Biscayne, Florida. (c)Al Bello/Getty Images/AFP

Kei Nishikori of Japan celebrates after defeating Alexandr Dolgopolov of Ukraine during their men's singles quarter-final match in the 2011 Shanghai Rolex Masters tennis tournament at the Qizhong Tennis Center in Shanghai on October 14, 2011. Nishikori won 6-4, 6-3. (c)MARK RALSTON / AFP

Switzerland's Roger Federer (R) poses with his trophy next to Japan's Kei Nishikori after winning his final match at the Swiss Indoors ATP tennis tournament match against Japan's Kei Nishikori on November 6, 2011 in Basel. Roger Federer won his fifth title at the Swiss Indoors and ends a ten-month title drought. (c)FABRICE COFFRINI / AFP

Kei Nishikori of Japan celebrates after his victory in the men's singles match against Jo-Wilfried Tsonga of France on the eighth day of the Australian Open tennis tournament in Melbourne on January 23, 2012. Nishikori won 2-6. 6-2. 6-1. 3-6. 6-3. (c)PAUL CROCK / AFP

Spanish tennis player Rafael Nadal (L) and Japan's Kei Nishikori (R) pose in front of the Sagrada Familia on April 24, 2012 in Barcelona to promote the Godo tennis tournament. (c)JOSEP LAGO / AFP

Japan's Kei Nishikori celebrates wining his game against Spain's David Ferrer during their men's singles tennis match third round at the 2012 London Olympic Games at the All England Tennis Club in Wimbledon, southwest London, on August 1, 2012. (c)LUIS ACOSTA / AFP

Kei Nishikori of Japan receives treatment from a trainer during his men's singles semi-final against Juan Monaco of Argentina at the ATP Malaysia Open tennis tournament in Kuala Lumpur on September 29, 2012. (c)MOHD RASFAN / AFP

Kei Nishikori of Japan celebrates his win over Milos Raonic of Canada while Japanese fans cheer during their men's final match at the Japan Open tennis tournament in Tokyo on October 7, 2012. Kei Nishikori won the match 7-6, 3-6, 6-0. (c)KAZUHIRO NOGI / AFP

Kei Nishikori of Japan holds the champion's trophy during the awards ceremony for the men's final at the Japan Open tennis tournament in Tokyo on October 7, 2012. Nishikori beat Milos Raonic of Canada 7-6, 3-6, 6-0 to take the title. (c)KAZUHIRO NOGI / AFP

Japanese Kei Nishikori returns the ball to French Benoit Paire during their Paris Tennis Masters Series indoor tournament match on October 30, 2012 at the Bercy Palais-Omnisport (POPB) in Paris. (c)LIONEL BONAVENTURE / AFP

Japanese tennis star Kei Nishikori attends a watch promotion in Tokyo on January 28, 2013. (c)RIE ISHII / AFP

Japanese player Kei Nishikori celebrates after winning his his men's singles third round tennis match against Swiss player Roger Federer at the Madrid Masters at the Magic Box (Caja Magica) sports complex in Madrid on May 9, 2013. Nishikori won the match 6-4, 1-6, 6-2. (c)JAVIER SORIANO / AFP

Japan's Kei Nishikori returns to Spain's Rafael Nadal during their French Tennis Open round of sixteen match at the Roland Garros stadium in Paris, on June 3, 2013. (c)MIGUEL MEDINA / AFP

Japan's Kei Nishikori leaves the court after being beaten in his third round men's singles match by Italy's Andreas Seppi on day six of the 2013 Wimbledon Championships tennis tournament at the All England Club in Wimbledon, southwest London, on June 29, 2013. Seppi won 3-6, 6-2, 6-7, 6-1, 6-4. (c)IAN KINGTON / AFP

Japan's tennis player Kei Nishikori (top) is tossed into the air by teammates as they celebrate the winning singles matches against Colombia in the Davis Cup World Group play-off in Tokyo on September 15, 2013. (c)KAZUHIRO NOGI / AFP

Japan's Kei Nishikori returns a shot to France's Richard Gasquet during their third round match at the ninth and final ATP World Tour Masters 1000 indoor tennis tournament on October 31, 2013 at the Bercy Palais-Omnisport (POPB) in Paris. (c)MIGUEL MEDINA / AFP

Former tennis professional John McEnroe of the US poses with Japan's Kei Nishikori (L) before their charity tennis match in Tokyo on November 17, 2013. (c)TORU YAMANAKA / AFP

Japan's Kei Nishikori gestures during his men's singles match against Spain's Rafael Nadal on day eight of the 2014 Australian Open tennis tournament in Melbourne on January 20, 2014. (c)GREG WOOD / AFP

Japan team players (front L to R) Yuichi Sugita, Go Soeda, Kei Nishikori and Yasutaka Uchiyama hold the national flag in celebration following their Davis Cup tennis 2014 World Group first round match victory over Canada in Tokyo on February 2, 2014. Japan beat Canada 4-1. (c)TOSHIFUMI KITAMURA / AFP

KEY BISCAYNE, FL - MARCH 26: Roger Federer of Switzerland at the net after his three set defeat congratulates Kei Nishikori of Japan during their quarter final round match during day 10 at the Sony Open at Crandon Park Tennis Center on March 26, 2014 in Key Biscayne, Florida. (c)Clive Brunskill/Getty Images/AFP

Japanese tennis player Kei Nishikori holds the trophy after beating Columbia's Santiago Giraldo during the ATP Final Barcelona Open "Conde de Godo" tennis tournament in Barcelona on April 27, 2014. (c)JOSEP LAGO / AFP

Japanese player Kei Nishikori receives treatment from a trainer during the men's singles final tennis match against Spanish player Rafael Nadal at the Madrid Masters at the Magic Box (Caja Magica) sports complex in Madrid on May 11, 2014. Rafael Nadal won his fourth title at the Madrid Masters, 2-6, 6-4, 3-0 when Kei Nishikori retired with a lower back injury. (c)PIERRE-PHILIPPE MARCOU / AFP

Japanese player Kei Nishikori (R) congratulates Spanish player Rafael Nadal at the end of the men's singles final tennis match of the Madrid Masters at the Magic Box (Caja Magica) sports complex in Madrid on May 11, 2014. Rafael Nadal won his fourth title at the Madrid Masters, 2-6, 6-4, 3-0 when Kei Nishikori retired with a lower back injury. (c)DANI POZO / AFP

Japan's Kei Nishikori celebrates winning his men's singles third round match against Italy's Simon Bolelli on day seven of the 2014 Wimbledon Championships at The All England Tennis Club in Wimbledon, southwest London, on June 30, 2014. Nishikori won. (c)ANDREW COWIE / AFP

NEW YORK, NY - SEPTEMBER 04: Kei Nishikori of Japan works with coach Michael Chang during a practice session on Day Eleven of the 2014 US Open at the USTA Billie Jean King National Tennis Center on September 3, 2014 in the Flushing neighborhood of the Queens borough of New York City. (c)AFP/Getty Images/Alex Goodlett

Kei Nishikori of Japan returns a shot to Stan Wawrinka of Switzerland during their 2014 US Open Men's Singles - Quarterfinals match at the USTA Billie Jean King National Tennis Center September 3, 2014 in New York. (c)TIMOTHY A. CLARY / AFP

Kei Nishikori of Japan throws his racquet while playing against Novak Djokovic of Serbia during their 2014 US Open men's semifinal singles match at the USTA Billie Jean King National Tennis Center September 6, 2014 in New York. (c)STAN HONDA / AFP

NEW YORK, NY - SEPTEMBER 06: Kei Nishikori of Japan celebrates after defeating Novak Djokovic of Serbia in their men's singles semifinal match on Day Thirteen of the 2014 US Open at the USTA Billie Jean King National Tennis Center on September 6, 2014 in the Flushing neighborhood of the Queens borough of New York City. Nishikori defeated Djokovic in four sets 6-4, 1-6, 7-6, 6-3. (c)Julian Finney/Getty Images/AFP

Marin Cilic of Croatia(R) and Kei Nishikori of Japan hold their awards after their US Open 2014 men's singles finals match at the USTA Billie Jean King National Center September 8, 2014 in New York. (c)STAN HONDA / AFP

Kei Nishikori, US Open tennis runner-up, displays a special package of the cup noodle designed with his celebration at the US Open, at the Nissin Food Products headquarters in Tokyo on September 16, 2014. Japanese tennis star Nishikori lost in the final to Croatian Marin Cilic 3-6, 3-6, 3-6 on September 8. (c)YOSHIKAZU TSUNO / AFP

Kei Nishikori of Japan tosses the ball to serve against Rajeev Ram of the US in the men's singles second round at the ATP Malaysia Open tennis tournament in Kuala Lumpur on September 24, 2014. (c)MOHD RASFAN / AFP

Kei Nishikori of Japan holds up the trophy during the awards ceremony after the men's singles final against Milos Raonic of Canada at the Japan Open tennis tournament in Tokyo on October 5, 2014. Nishikori won 7-6 (7/5), 4-6, 6-4. (c)KAZUHIRO NOGI / AFP

Kei Nishikori of Japan (2nd R) is congratulated by his coach Michael Chang (C) after the men's singles final against Milos Raonic of Canada at the Japan Open tennis tournament in Tokyo on October 5, 2014. Nishikori won 7-6 (7/5), 4-6, 6-4. (c)KAZUHIRO NOGI / AFP

Japan's Kei Nishikori returns a ball to Spain's David Ferrer during a quarter-final match at the ATP World Tour Masters 1000 indoor tennis tournament on October 31, 2014 at the Bercy Palais-Omnisport (POPB) in Paris. (c)FRANCK FIFE / AFP

Japanese tennis player Kei Nishikori speaks before the press at Japan's national press club in Tokyo on November 18, 2014. World's fifth ranked tennis player Nishikori, the highest ever by an Asian man, returned from season's last game Grand Slam final after he lost the semi-final by world's top ranked Novak Djokovic. (c)YOSHIKAZU TSUNO / AFP

Japanese tennis player Kei Nishikori (C) is welcomed by his fans during a fan event in Tokyo on November 21, 2014. Nishikori enjoyed a breakthrough campaign in 2014 as the Japanese star reached his maiden Grand Slam final at the US Open and became the first Asian singles player to qualify for the prestigious season-ending Tour Finals after climbing to fifth in the world rankings. (c)TORU YAMANAKA / AFP

Japanese tennis player Kei Nishikori (L) shakes hands with US tennis legend Andre Agassi after their exhibition match in Tokyo on November 22, 2014. (c)TORU YAMANAKA / AFP

Kei Nishikori of Japan holds a koala on the sidelines of day three of the Brisbane International tennis tournament in Brisbane on January 6, 2015. (c)SAEED KHAN / AFP

Kei Nishikori of Japan hits a return against Stan Wawrinka of Switzerland in their men's singles match on day 10 of the 2015 Australian Open tennis tournament in Melbourne on January 28, 2015. (c)MAL FAIRCLOUGH / AFP

ACAPULCO, MEXICO - MARCH 01: Tennis Pro Kei Nishikori Enjoying Some Down Time In Acapulco, Mexico on March 1, 2015 in Acapulco, Mexico. (c)Vivien Killilea/Getty Images for Leisure Opportunities/AFP

Fans of Japanese tennis player Kei Nishikori follow him after attending a training session at the Barcelona Open "Conde de Godo" tennis tournament in Barcelona on April 20, 2015. (c)QUIQUE GARCIA / AFP

Japanese tennis player Kei Nishikori celebrates his victory over Spanish tennis player Pablo Andujar at the end of the final of the ATP Barcelona Open "Conde de Godo" tennis tournament in Barcelona on April 26, 2015. Nishikori won 6-4, 6-4. (c)JOSEP LAGO / AFP

Japanese tennis player Kei Nishikori poses with his trophy and a Japanese flag as he celebrates his victory over Spanish tennis player Pablo Andujar after the final of the ATP Barcelona Open "Conde de Godo" tennis tournament in Barcelona on April 26, 2015. Nishikori won 6-4, 6-4. (c)JOSEP LAGO / AFP

Japan's Kei Nishikori returns the ball to Brazil's Thomaz Belluci during the men's second round of the Roland Garros 2015 French Tennis Open in Paris on May 27, 2015. (c)KENZO TRIBOUILLARD / AFP

Japan's Kei Nishikori reacts during his match against Germany's Dustin Brown during the ATP Gerry Weber Open round of sixteen tennis match in Halle, western Germany on June 18, 2015. Nishikori won the match 7-5 and 6-1. (c)MAJA HITIJ / DPA / AFP

Japan's Kei Nishikori prepares to return against Italy's Simone Bolelli during their men's singles first round match on day one of the 2015 Wimbledon Championships at The All England Tennis Club in Wimbledon, southwest London, on June 29, 2015. (c)LEON NEAL / AFP

WASHINGTON, DC - AUGUST 09: Kei Nishikori of Japan celebrates after defeating John Isner of the United States in the men's singles final during the Citi Open at Rock Creek Park Tennis Center on August 9, 2015 in Washington, DC. (c)Patrick Smith/Getty Images/AFP

NEW YORK, NY - AUGUST 26: Kei Nishikori attends the 2nd Annual Delta OPEN Mic With Serena Williams at Arena on August 26, 2015 in New York City. (c)Michael Loccisano/Getty Images for Delta/AFP

Japan's Kei Nishikori celebrates after winning a Copa Davis World Group play off match against Colombian Alejandro Falla in Pereira, Risaralda department, on September 18, 2015. Nishikori won 7-6, 7-6, 7-5. (c)RAUL ARBOLEDA / AFP

Kei Nishikori of Japan reacts after winning a point against Marin Cilic of Croatia during their quarter-final match at the Japan Open tennis tournament in Tokyo on October 9, 2015. (c)TORU YAMANAKA / AFP

Japan's Kei Nishikori arives on court for his third round tennis match against France's Richard Gasquet at the ATP World Tour Masters 1000 indoor tennis tournament in Paris on November 5, 2015. (c)MIGUEL MEDINA / AFP

Japan's Kei Nishikori returns the ball to Czech Republic's Tomas Berdych during their men's singles group stage match on day three of the ATP World Tour Finals tennis tournament in London on November 17, 2015. Nishikori won the match 7-5, 3-6, 6-3. (c)GLYN KIRK / AFP

LOS ANGELES, CA - DECEMBER 13: Kei Nishikori and Maria Sharapova at the Maria Sharapova and Friends tennis event presented by Porsche on December 13, 2015 in Los Angeles, California. (c)Angela Weiss/Getty Images for Porsche/AF

Japan's Kei Nishikori hits a return against Mikhail Kukushkin of Kazakhstan during their men's singles match on the fourth day of the Brisbane International tennis tournament on January 6, 2016. (c)SAEED KHAN / AFP

Japan's Kei Nishikori returns against France's Jo-Wilfried Tsonga during their men's singles on day seven of the 2016 of the Australian Open tennis tournament in Melbourne on January 24, 2016. (c)GREG WOOD / AFP

MEMPHIS, TN - FEBRUARY 14: Kei Nishikori of Japan celebrates with the trophy after defeating Taylor Fritz of the United States in their singles final match on Day 7 of the Memphis Openat the Racquet Club of Memphis on February 14, 2016 in Memphis, Tennessee. (c)Stacy Revere/Getty Images/AFP

Kei Nishikori of Japan signs autographs after his match against Mikhail Kukushkin of Kazakhstan in 2nd round action during the BNP Paribas Open at the Indian Wells Tennis Garden on March 13, 2016, in Indian Wells, California. (c)ROBYN BECK / AFP

Kei Nishikori of Japan reacts during the semifinal match of the ATP Tennis Open tournament game against Croatia's Novak Djokovic at the Foro Italico in Rome on May 14, 2016. (c)FILIPPO MONTEFORTE / AFP

Japan's Kei Nishikori serves the ball to Spain's Fernando Verdasco during their men's third round match at the Roland Garros 2016 French Tennis Open in Paris on May 27, 2016. (c)Thomas SAMSON / AFP

Japan's Kei Nishikori returns the ball to France's Richard Gasquet during their men's fourth round match at the Roland Garros 2016 French Tennis Open in Paris on May 29, 2016. (c)PHILIPPE LOPEZ / AFP

Japan's Kei Nishikori poses for a photograph at the practice courts at The All England Tennis Club in Wimbledon, southwest London, on June 26, 2016, on the eve of the start of the 2016 Wimbledon Championships tennis tournament. (c)ADRIAN DENNIS / AFP

Japan's Kei Nishikori returns to France's Julien Benneteau during their men's singles second round match on the fourth day of the 2016 Wimbledon Championships at The All England Lawn Tennis Club in Wimbledon, southwest London, on June 30, 2016. (c)JUSTIN TALLIS / AFP

Kei Nishikori of Japan against Stan Wawrinka of Switzerland during the men's semi-finals Rogers Cup tennis action in Toronto, Canada July 30, 2016. (c)KEVIN VAN PAASSEN / AFP)

Japan's Kei Nishikori celebrates after beating Spain's Rafael Nadal in their men's singles bronze medal tennis match at the Olympic Tennis Centre of the Rio 2016 Olympic Games in Rio de Janeiro on August 14, 2016. (c)JAVIER SORIANO / AFP

Gold medallist Britain's Andy Murray (C), silver medallist Argentina's Juan Martin Del Potro (L), bronze medallist Japan's Kei Nishikori pose on the podium of the men's singles gold medal tennis event at the Olympic Tennis Centre of the Rio 2016 Olympic Games in Rio de Janeiro on August 14, 2016. (c)Luis Acosta / AFP

NEW YORK, NY - SEPTEMBER 07: Kei Nishikori of Japan reacts against Andy Murray of Great Britain during their Men's Singles Quarterfinal match on Day Ten of the 2016 US Open at the USTA Billie Jean King National Tennis Center on September 7, 2016 in the Flushing neighborhood of the Queens borough of New York City. (c)Mike Hewitt/Getty Images/AFP

Kei Nishikori of Japan hits a return against Stan Wawrinka of Switzerland during their 2016 US Open Men’s Singles semifinal match at the USTA Billie Jean King National Tennis Center in New York on September 9, 2016.(c)Jewel SAMAD / AFP

Kei Nishikori (L) of Japan makes grimaces as he talks with a doctor and a trainer during the men's singles second round match against Joao Sousa of Portugal before withdrawing from the match due to injury at the ATP Japan Open tennis tournament in Tokyo on October 5, 2016. (c)TORU YAMANAKA / AFP

Japan's Kei Nishikori reacts after a point against Croatia's Marin Cilic during their round robin stage men's singles match on day six of the ATP World Tour Finals tennis tournament in London on November 18, 2016. (c)Glyn KIRK / AFP

Tennis players Rafael Nadal of Spain (L) and Kei Nishikori of Japan (R) handle a 10-month old wombat called Lola in front of the Sydney Harbour Bridge, in Sydney on January 9, 2017. - Top tennis players are gathering in Australia in the lead up to the Australia Open tennis tournament in Melbourne which runs January 16-19. (c)WILLIAM WEST / AFP

Switzerland's Roger Federer (R) shakes hands with Japan's Kei Nishikori after winning their men's singles fourth round match on day seven of the Australian Open tennis tournament in Melbourne on January 22, 2017. (c)SAEED KHAN / AFP

Japan's tennis player Kei Nishikori prepares to serve against Brazil's Thomaz Bellucci during their ATP World Tour 500 Rio Open at Jockey Club in Rio de Janeiro, Brazil, on February 21, 2017. (c)Yasuyoshi Chiba / AFP

INDIAN WELLS, CA - MARCH 15: Kei Nishikori of Japan plays a forehand against Donald Young of the United States in their fourth round match during day ten of the BNP Paribas Open at Indian Wells Tennis Garden on March 15, 2017 in Indian Wells, California. (c)Clive Brunskill/Getty Images/AFP

Japanese tennis player Kei Nishikori drops his racket during his match against Spanish player David Ferrer at the ATP Madrid Open in Madrid, on May 11, 2017. (c)OSCAR DEL POZO / AFP

Japan's Kei Nishikori celebrates after scoring a point during his tennis match against Spain's Fernando Verdasco at the Roland Garros 2017 French Open on June 5, 2017 in Paris. (c)Lionel BONAVENTURE / AFP

Japan's Kei Nishikori throws his racquet after a point against Spain's Roberto Bautista Agut during their men's singles third round match on the fifth day of the 2017 Wimbledon Championships at The All England Lawn Tennis Club in Wimbledon, southwest London, on July 7, 2017. (c)Daniel LEAL-OLIVAS / AFP

NEWPORT BEACH, CA - JANUARY 23: Kei Nishikori of Japan reacts after losing a point to Dennis Novikov during the first round of the Oracle Challenger Series at the Newport Beach Tennis Club on January 23, 2018 in Newport Beach, California. (c)Jeff Gross/Getty Images/AFP

Japan's Kei Nishikori celebrates after his victory against Germany's Alexander Zverev during their semi final match at the Monte-Carlo ATP Masters Series tournament on April 21, 2018 in Monaco. (c)YANN COATSALIOU / AFP

Japan's Kei Nishikori celebrates after winning his match against Bulgaria's Grigor Dimitrov during Rome's ATP Tennis Open tournament at the Foro Italico, on May 16, 2018 in Rome. (c)Andreas SOLARO / AFP

Japan's Kei Nishikori plays a backhand return to France's Maxime Janvier during their men's singles first round match on day one of The Roland Garros 2018 French Open tennis tournament in Paris on May 27, 2018. (c)CHRISTOPHE SIMON / AFP

Japan's Kei Nishikori returns to Australia's Nick Kyrgios in their men's singles third round match on the sixth day of the 2018 Wimbledon Championships at The All England Lawn Tennis Club in Wimbledon, southwest London, on July 7, 2018. (c)Oli SCARFF / AFP

Men's singles semi-finalist Kei Nishikori of Japan and women's singles semi-finalist Naomi Osaka of Japan pose for a portrait outside The Kitano Hotel following their quarter-final matches on day 10 of the 2018 US Open at The Kitano Hotel on September 5, 2018 in New York City. (c)Alex Pantling/Getty Images/AFP

Kei Nishikori of Japan celebrates match point during his men's singles quarter-final match against Marin Cilic of Croatia on Day Ten of the 2018 US Open at the USTA Billie Jean King National Tennis Center on September 5, 2018 in the Flushing neighborhood of the Queens borough of New York City. (c)Elsa/Getty Images/AFP

Japanese tennis player Kei Nishikori returns a ball to German tennis player Matthias Bachinger during their ATP Moselle semi-final tennis match on September 22, 2018 in Metz, eastern France. - Bachinger won 2/6, 6/4, 7/5. (c)JEAN-CHRISTOPHE VERHAEGEN / AFP

Kei Nishikori of Japan hits a return against Wu Yibing of China during their men's singles second round match at the Shanghai Masters tennis tournament on October 10, 2018. (c)Johannes EISELE / AFP

Japan's Kei Nishikori serves the ball to France's Adrian Mannarino during their men's singles second round tennis match on day three of the ATP World Tour Masters 1000 - Rolex Paris Masters - indoor tennis tournament at The AccorHotels Arena in Paris, on October 31, 2018. (c)Anne-Christine POUJOULAT / AFP

Japan's Kei Nishikori reacts after winning a point against Switzerland's Roger Federer during their singles round robin match on day one of the ATP World Tour Finals tennis tournament at the O2 Arena in London on November 11, 2018. (c)Glyn KIRK / AFP

Japan's Kei Nishikori lifts his winning trophy at the end of men's singles final match at the Brisbane International tennis tournament in Brisbane on January 6, 2019.(c)Saeed Khan / AFP

Japan's Kei Nishikori celebrates his victory against Spain's Pablo Carreno Busta during their men's singles match on day eight of the Australian Open tennis tournament in Melbourne on January 21, 2019. (c)Greg Wood / AFP

Japan's Kei Nishikori serves the ball to France's Benoit Paire during their men's singles fourth round match on day eight of The Roland Garros 2019 French Open tennis tournament in Paris on June 2, 2019. (c)Anne-Christine POUJOULAT / AFP

Japan's Kei Nishikori returns against Switzerland's Roger Federer during their men's singles quarter-final match on day nine of the 2019 Wimbledon Championships at The All England Lawn Tennis Club in Wimbledon, southwest London, on July 10, 2019. (c)Adrian DENNIS / AFP

Japan's Kei Nishikori serves the ball to Russia's Karen Khachanov during their men's singles second round tennis match on Day 4 of The Roland Garros 2021 French Open tennis tournament in Paris on June 2, 2021. (c)MARTIN BUREAU / AFP

Japan's Kei Nishikori celebrates during his Tokyo 2020 Olympic Games men's singles third round tennis match against Belarus' Ilya Ivashka at the Ariake Tennis Park in Tokyo on July 28, 2021. (c)Tiziana FABI / AFP

(L to R) Japanese tennis player Kei Nishikori, retired tennis legend Roger Federer of Switzerland, Japanese wheelchair tennis player Shingo Kunieda and British wheelchair player Gordon Reid pose for photos as they attend a promotional event at the Ariake Coliseum in Tokyo on November 19, 2022. (c)Richard A. Brooks / AFP

Japan's Kei Nishikori playing with Japan's Taro Daniel, returns during their men's doubles first round tennis match against Britain's Andy Murray and Britain's Daniel Evans on Court Suzanne-Lenglen at the Roland-Garros Stadium at the Paris 2024 Olympic Games, in Paris on July 28, 2024. (c)MARTIN BERNETTI / AFP