Naomi Osaka reacts on Instagram as her coach confirms he’s departing the team

In September 2024, Mouratoglou joined Osaka’s team, bringing Guillaume Brunoir, a strength and conditioning coach from his academy, with him.

Although the Frenchman left in July, Brunoir had stayed with the Japanese star until now, when they finally went their separate ways.

The decision was confirmed by the coach on his Instagram, where he posted: “Some chapters are meant to leave a mark. From Los Angeles to Osaka, through every court, every session, every challenge. Quiet focus, fleeting moments, unseen efforts, and the laughter we shared along the way.

“Proud of the work, the growth, and the bond built during these months. Thankful for the path we shared. Ready for the next move.”

The split appears to be amicable with no hard feelings between them, as Osaka responded to his post with: “Thanks for everything. Wishing you the best on what’s to come!”

2025 shows signs of progress for Naomi Osaka

Osaka’s season did not wrap up the way she would have liked, but 2025 has still shown clear progress compared to last year.

After returning from maternity leave in 2024, she struggled to regain her form and never broke back into the top 50.

This season, though, has been a different story. The four-time Grand Slam champion is now ranked world number 16 and has looked more consistent throughout the year.

During Mouratoglou’s time in charge, she won her first title at a lower-level WTA 125 event in Saint-Malo. The Japanese player also reached finals at both the Canadian Open and Auckland International.

The biggest leap forward has come in Grand Slam performances. In 2024, she did not get past the second round of any major. This year, she made it to at least the third round in every one.

The highlight was reaching the US Open semifinals for the first time since her title run in 2020.

The one area still needing work is her record against top-10 opponents. She has managed just one win in five attempts this year, with that lone victory coming over Coco Gauff at the US Open.