Japan's Naomi Osaka, a four-time Grand Slam singles champion, will work with Polish coach Tomasz Wiktorowski on a trial basis after splitting with Patrick Mouratoglou after less than a year together.

The former world No 1 will work with Polish coach Tomasz Wiktorowski on a trial basis after ending the short-lived partnership.

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