Defending Australian Open champion Naomi Osaka on Saturday allayed fears about an abdominal injury that forced the Japanese former world No. 1 to withdraw from a tune-up event last week.

Playing her first tournament in four months, the 24-year-old won three matches in the WTA 250 event but then withdrew ahead of her semifinal, raising doubts about her preparations for her title defense at Melbourne Park.

"I heal quite fast," Osaka told reporters with a smile. "I'm as good as I can be in this current moment.