Osaka has won only one title while collaborating with Mouratoglou – more precisely the Saint-Malo WTA 125 – really too little for a champion of her caliber, who has made the recent history of women's tennis by becoming a point of reference for all her rivals.

Tennis coach Rick Macci has highlighted what Naomi Osaka needs to do to return to her very best. Former world number one Osaka has had a tough time ever since returning to court after taking a long break to deal with pregnancy.

Naomi Osaka and coach Patrick Mouratoglou are done working together after less than a year, the four-time Grand Slam champion announced Sunday on social media. "Merci Patrick," Osaka began her post, with a photo of her hitting a practice serve while he stands nearby.