Just two weeks out from Wimbledon, Kei Nishikori, once a US Open finalist and Japan’s biggest tennis hope, pulled out of the tournament with yet another injury setback. He’d already skipped the Italian Open, retired mid-match in Geneva, and withdrawn from Roland Garros before hitting a single ball, missing a clash with eventual champion Carlos Alcaraz. But while Nishikori struggles to get back in form on the court, it’s his personal life that’s now stealing the spotlight, and for all the wrong reasons.

Nishikori married his longtime partner, Mai Yamauchi, in December 2020. They’d been together since 2015, and by all appearances, theirs was a steady, private relationship. The couple went on to have two children—one born in May 2021, and their second arriving in 2024. Two years after tying the knot, they celebrated with a wedding ceremony and reception in December 2022. But behind the scenes, things weren’t as picture-perfect as they seemed.

According to a report by Shukan Bunshun, Kei Nishikori had already begun an affair with model Oguchi Azuki in 2022, just days before that wedding celebration. The two allegedly first connected in Hawaii, during a tour stop, where Nishikori is said to have approached her. What started casually soon turned serious, even though Oguchi was reportedly unaware of the timing or just how entangled Nishikori already was. At some point, the relationship was said to have ended, but not for long. On the night of June 11, 2025, Nishikori was reportedly seen visiting Azuki’s apartment, sparking new rumors that the affair had continued.

With growing speculation and backlash, Kei Nishikori issued a public apology according to Bunshun and said, “I deeply apologize for causing discomfort to everyone who supports me—tennis fans, tennis associations, sponsors, and other related parties—and for their concern and inconvenience due to my dishonest behavior. In addition, I deeply regret that I made my wife, children, and each parent feel hurt. From now on, in order to fulfill my life as a responsible member of society, I will solely focus on tennis competitions and produce results. We will do our best to regain your trust.” 

The Japanese star is also struggling on the court, with injuries derailing his career.

Kei Nishikori’s struggles continue as injury causes setback again

“Of course, I’ve had a lot of injuries, but I’ve never felt like I’ve finished,” he said. “I’ve never lost the motivation to come back.”

After reaching the peak of his career with a runner-up finish at the 2014 US Open and climbing to a career-high ranking of No. 4 in 2015, Kei Nishikori’s journey has since been plagued by injuries. A persistent wrist issue kept him off the tour for extended stretches and saw his ranking take a sharp tumble. Just as he began to regain momentum, another setback arrived—hip surgery in 2022 that once again halted his progress.

His road back has been anything but easy. It wasn’t until late 2024 that the 35-year-old began showing real signs of recovery, culminating in a runner-up finish at the Hong Kong Open this year. That result helped him break back into the top 100 at the start of the 2025 season, sparking hopes of a full-fledged comeback.

But injuries have continued to haunt him. Since early 2022, Kei Nishikori has featured in just three Grand Slam main draws, the most recent being the Australian Open earlier this year. He was forced to pull out of Roland Garros before playing a match and has now withdrawn from Wimbledon. At SW19, his best showings remain his quarterfinal runs in 2018 and 2019.

Nishikori’s return to the top has been derailed by more than just injuries. With a cheating scandal now making headlines, his toughest fight might be off the court.