Naomi Osaka reveals that she didn't think she'd get along with coach Patrick Mouratoglou at first

In her first four months working with coach Patrick Mouratoglou, Naomi Osaka has learned an important lesson: Don't judge a book by its cover.

The former world No. 1 confessed this week at the Australian Open that she didn't think she'd get along with the "straight-laced" French trainer, the former coach of Serena Williams and others, when she first hired him last September, but has quickly grown to appreciate the 54-year-old's lighter side.

"It's funny, I've told people this. In the very beginning I was a little wary of him just because his persona is very... I didn't know if I would get along with him," she said..

"But he's actually really funny, very hilarious. I didn't really expect that from him because I thought he was so straight-laced. He's very funny."

Mouratgolou has been a calming, supportive presence for Osaka's since teaming up with her last fall, particularly in light of the injury struggles that the former world No. 1 has experienced in the first months of their partnership. A back problem ended her 2024 comeback season following maternity leave prematurely, and a recurring abdominal injury forced her to retire in her first two tournaments of 2025: up a set in the final of the ASB Classic, and the third round of the Australian Open.

"Sad to finish a tournament this way, even more a Grand Slam," Mouratoglou wrote on Instagram after Osaka was forced to retire against Belinda Bencic in the third round in Melbourne. "You did everything you could fighting with injury since Round 1. You can be proud of yourself. Let’s take the time to heal and come back even stronger!"

Mouratoglou also came to Osaka's defense following a candid interview she gave at the start of the season, where she said that she wouldn't "hang around" in tennis if she couldn't get back to her best level.

Read more: Naomi Osaka says she won't 'hang around' in tennis if the results don't come

"I totally understand. When you've been a multiple Grand Slam winner, I think it's very difficult mentally to be far from the level that you know you can play," he said of Osaka, who came into the Australian Open ranked No. 51. "I don't see her playing to be Top 20. ... She wants to win, she wants to feel that she's great at what she's doing, and I think it's a good thing, because if you accept to be Top 20, there is no chance you're going to win a Grand Slam. You have to refuse to be at certain level, because you deserve better, or you think you're able to do better.

"It's not disrespectful for anybody else. It's just something between you and yourself, so she's right to say that it's not disrespectful to anyone."

While the full extent of Osaka's injury is unclear, she hinted at a few weeks off when she met reporters after retiring against Bencic, saying she hoped to be able to "get it together in time for the U.S. swing" in Indian Wells and Miami in March.