Osaka in crisis! Splits with coach as ranking drops

Osaka splits with coach Fissette

Naomi Osaka has parted ways with coach Wim Fissette after four years together across two stints, the 26-year-old announced late on Friday.

The former world number one won two of her four Grand Slam titles under the guidance of the Belgian, but is currently 75th in the rankings having returned to the tour nine months ago after a lengthy maternity break.

"Four years, two slams and a whole lot of memories," Osaka wrote in an Instagram post.

"Thanks Wim for being a great coach and an even greater person. Wishing you all the best."

Of the 16 tournaments Osaka has played this season, she has made the quarter-finals in only two - Doha and 's-Hertogenbosch - and the Japanese player has also failed to go past the second round in each of the four Grand Slams.

Swiatek to miss Korea Open due to fatigue, Pegula out with injury

World number one Iga Swiatek has pulled out of the Korea Open due to fatigue, tournament organisers told reporters on Friday.

Defending champion and U.S. Open finalist Jessica Pegula has also pulled out from the WTA 500 event in Seoul with a rib injury.

Poland's Swiatek, who won the French Open in June and took bronze in the Paris Olympics before losing to Pegula in the U.S. Open's quarter-finals, had also withdrawn from last month's Canadian Open citing fatigue.

Former Wimbledon champion and world number four Elena Rybakina will also miss the Korea Open with a back injury, while U.S. Open semi-finalist Emma Navarro has pulled out due to a change of schedule.

Korea Open will take place between Sept. 16-22.