Naomi Osaka is reportedly set to work with Tomasz Wiktorowski, the former coach of Iga Swiatek. The four-time Major winner announced her sudden split from Patrick Mouratoglou on Sunday, days after Emma Raducanu beat her in the second round of the WTA 500 in Washington.

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.

Osaka's time with Mouratologou followed an up-and-down sequence of promising signs and frustrations with either injury or close-run defeats.