Maria Sharapova has pulled out of the Brisbane International because of a collarbone issue.
The world number two withdrew ahead of her second-round clash against Jarmila Gajdosova on Tuesday, just days after pulling out of an exhibition game in Seoul.
"That's why I had to pull out of the exhibition match I had in [South] Korea (against Caroline Wozniacki in December)," she told reporters on Tuesday.
"I had a bit of inflammation in my collarbone. My doctor in New York told me I couldn't really do much overhead training for about a week.
"So to be fair, I haven't really given myself a chance to pretty much hit any serves or anything over my head. Just been practicing groundstrokes. So I just kind of ran out of time here."
Sharapova is now determined to make a successful recovery for the Australian Open.
"I still have quite a bit of time to prepare for the Australian Open," she said. "I'm on the right track, been training really well, so I just don't want to jeopardise what I've gained in the off-season so far.
"I just have to make a smart move here."
The Australian Open starts on January 14.