Maria Sharapova will sit out the U.S. Open because of a bad right shoulder, the first major championship she'll miss since her Grand Slam debut in 2003.

The three-time Grand Slam title winner already had announced she's pulling out of the Beijing Olympics because of the injury. Sharapova said in a posting on her Web site Friday she probably won't need surgery and could be ready to play in two to three months.

"It hurts me so much to miss the Olympics and the U.S. Open, you have no idea," she said. "Just to type those words hurt!!"

Earlier Friday, a U.S. Open official told The Associated Press that Sharapova's agent informed the tournament she wouldn't be able to play in the year's last Grand Slam event.

The No. 3-ranked Sharapova has played in each of the past 23 major championships, winning titles at Wimbledon in 2004, the U.S. Open in 2006 and the Australian Open in January.

A doctor who looked at tests on her shoulder from April and this week told Sharapova she has been playing with a torn rotator cuff tendon since the spring.