36-Year-Old Kei Nishikori, Limited to Challenger Tour This Year, to Retire at Japan Open

Kei Nishikori will conclude his professional career at the Japan Open in Tokyo after receiving a wild card invitation from tournament organizers. The ATP Tour confirmed the entry Tuesday. The event begins Sept.

4. U.S. Open final, becoming the first Japanese man to advance to the title match at a Grand Slam singles tournament. He lost that match in straight sets to Marin Cilic.

He also won a bronze medal at the 2016 Rio de Janeiro Olympics after defeating Rafael Nadal. Nishikori reached a career-high ranking of No. 4 on two occasions. Michael Chang, who coached him, told The Associated Press that the achievement stands out because it came during the era of the Big Three and Big Four.

"4 in the world on two different occasions is not easy," Chang said. Nishikori made his professional debut in 2007 and was the highest-ranked Japanese man in ATP history. After years of injury problems, he competed exclusively on the lower-tier Challenger tour this year.

Naomi Osaka, a four-time Grand Slam champion, said Nishikori's accomplishments inspired Japanese players. "Being Japanese, being able to look up to him, seeing everything he's achieved, in a world where Japanese tennis hasn't been able to go as far as he did in that moment in time, it was just so inspiring," Osaka said. She added that she wanted to see him play one more time.

Chang said Nishikori deserves a strong send-off in Tokyo.