Maria withdraws from Stuttgart

Maria Sharapova has been forced to withdraw from next week's WTA event in Stuttgart due to a shoulder injury, it was revealed on Wednesday.

The 20-year-old Russian, ranked number four in the world, has had problems with her right shoulder ever since the WTA tournament in Miami earlier this year and has recently suffered a lot of pain when serving.

As a result, the 2004 Wimbledon winner has not played a tournament since the US Open, where she lost in the third round.

Sharapova is expected to make a comeback at the WTA event in Madrid this November.

"I was really looking forward to the Stuttgart tournament and I'm very sorry my injury hasn't cleared up in time," said Sharapova.

"I'll do everything to be able to return to the tour as quickly as possible."

Despite Sharapova's withdrawal, there is still a strong field for the indoor event with nine of the world's top 10 players including defending champion Nadia Petrova.