Naomi Osaka has parted company with coach Patrick Mouratoglou less than a year after the pair began working together, the four-times Grand Slam champion said days after her defeat to Emma Raducanu at the Washington Open.

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.

Wiktorowski’s first work in the role for Osaka will come at the Canadian Open as Osaka gears up for the US Open next month. Osaka defeated Canadian Ariana Arseneault in the Round of 128 and will face No.