Former world No. 1 Naomi Osaka retired from the ASB Classic final in Auckland on Sunday due to an abdominal injury after winning the first set against Clara Tauson.

Naomi Osaka’s fitness for the Australian Open is in question after the four-time Grand Slam champion and former No. 1 suffered an apparent abdominal injury while playing the final of a WTA tournament in Auckland.

The former world No. 1 and four-time Grand Slam champion retired from the final of the WTA Auckland Open, the last tune-up before the Australian Open, with an apparent medical issue on Sunday. She had been leading Denmark's Clara Tauson 6-4, but her exit left Tauson as the tournament's champion.