Sharapova still strengthening shoulder after injury
Maria Sharapova has admitted her shoulder is not yet at full strength after last year's injury.
Sharapova hurt her shoulder during the clay season, and after an opening-round defeat in Cincinnati, she did not play the rest of the year. The Russian also had surgery on the shoulder in 2008.
She told reporters in Miami that she has recovered from the problem but is still working to rebuild fitness.
"My shoulder feels good," she said. "Missing five or six months of the season last year, it takes a lot to build up the strength in it again."
Sharapova lost to Camila Giorgi in the third round of Indian Wells, her first event since taking a break to promote the Winter Olympics, which were held in her hometown of Sochi.
"It's one thing to come off and heal the injury, it's another thing building that stamina in the shoulder to play a three-set match," Sharapova said. "That's something I'm still working on and it's not at the level I want it to be."