Coach Wim Fissette and Naomi Osaka have ended their working relationship, according to an Instagram post by Fissette written on Wednesday.

"It has been a privilege to coach Naomi since 2019 and see her grow into the champion she has become," Fissette wrote. "She has inspired a whole new generation to fall in love with the game & to speak up for what they believe in.

"It’s been incredible to play a part in that journey. Thank you ... I wish you all the best and looking forward to my next chapter."

Osaka was Fissette's latest high-profile charge on the Hologic WTA Tour. Prior to Osaka, the Belgian worked with compatriot Kim Clijsters, as well as other former World No. 1s Victoria Azarenka, Simon Halep and Angelique Kerber, among others.

Their working relationship began at the start of the 2020 season, and together, Fisette helped guide Osaka to two of her four Grand Slam titles. She won the 2020 US Open and 2021 Australian Open under Fissette's tutelage. This season, after falling to as low as No. 85 in the rankings, a resurgent Osaka reached her first final in more than a year at the Miami Open, where she was beaten by Iga Swiatek. 

Osaka has been sidelined due to an Achilles injury since a Round 1 loss at Roland Garros in May, but she's expected to make her return in two weeks at the Mubadala Silicon Valley Classic in San Jose. The former World No. 1 has accepted a wild card for the WTA 500 event, which begins Aug. 1.