MELBOURNE, Australia - Now that Maria Sharapova knows what is wrong with her sore right shoulder, she's confident she can play through the pain at next week's Australian Open.

Sharapova, who won her first Grand Slam title at age 17 in 2004 and rose to No. 1 in the rankings for two short periods last year, traveled to Melbourne unsure if she'd be fit enough to play in the season's first major.

After months of pain, the Russian star said doctors had identified that her problem stemmed from a dislocated rib, not a pectoral muscle problem.

"It's not 100 percent. I wouldn't say it's at the top level. But at least I know the cause of the problem," Sharapova said Thursday. "The good thing is, the doctors have told me it can't get any worse.