OAKLAND, Aug 2: Russian world No 3 Maria Sharapova will miss the US Open starting later this month and could be sidelined for up to three months after an examination of her injured right shoulder revealed a torn rotator cuff.

After examining Sharapova's scan, Dr David Altchek determined the injury would not require surgery but said she could be out of action for the rest of the season.

Sharapova, 21, had already announced on Thursday she would not take part in the Beijing Olympics after the sore shoulder forced her to withdraw from the Montreal Cup following a second round 7-5, 5-7, 6-2 win over Poland's Marta Domachowska.

The Australian Open champion has only played thrice since losing to Dinara Safina in the fourth round of the French Open.

“The doctor does not believe that I need surgery and is sending me to work with a specialist in Arizona next week to do extensive rehab and strength work and he believes that I should be ready to play in two to three months,” Sharapova said on Friday.

“It hurts me so much to miss the Olympics and the US Open. I think this will be the first Grand Slam I have ever missed.”

Sharapova first re-injured her shoulder at Indian Wells in March when stretching for a backhand against Alona Bondarenko.

“Altchek looked at all my tests from April and today and informed me that I have been playing with a moderate tear in my rotator cuff tendon since April,” she said. “He actually couldn't believe that I've been playing this long with this injury.

“You can imagine that I was not very thrilled to hear that my medical team did not see this tear in my shoulder back in April.”

The US Open starts from Aug 25 in New York.—Reuters