Naomi Osaka splits with tennis coach Wim Fissette

July 21 (UPI) -- Tennis star Naomi Osaka and coach WIm Fissette ended their long partnership, Fissette announced on social media.

Fissette announced the end of his tenure with the four-time Grand Slam champion Wednesday on Instagram.

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

"Thank you Naomi Osaka. I wish you all the best and looking forward to my next chapter."

Osaka had not commented about the split on social media as of Thursday morning, but it is not uncommon for tennis stars and their coaches to part ways.

Earlier this year, Serena Williams split with longtime coach Patrick Mouratoglou. Mouratoglou went on to work with Simona Halep, who split with her former coach last year.

Fellow women's tennis star Iga Swiatek, the No. 1 player in the world, announced in December that she split with former coach Piotr Sierzputowski.

Osaka won the 2018 U.S. Open and 2019 Australian Open while with former coach Sascha Bajin. She split with Bajin shortly after her title in Melbourne. She then worked with Jermaine Jenkins and her father. She hired Fissette just before the 2020 season.

Fissette previously worked with Simona Halep, Victoria Azarenka, Angelique Kerber and other tennis stars.

Osaka, 24, is the No. 38 player in the WTA singles rankings. She lost in the third round of January's Australian Open and in the first round of the French Open four months later in Paris.

Osaka withdrew from Wimbledon in June with an injured Achilles tendon. She is on the entry list for the 2022 U.S. Open's main draw, which was released Wednesday by tournament organizers.

The final Grand Slam of the season will run from Aug. 29 to Sept. 11 at the USTA Billie Jean King National Tennis Center in Flushing, N.Y.

She also is expected to play in the Mubadala Silicon Valley Classic, which will start Aug. 1 in San Jose, Calif.