Philadelphia, PA -- (Sports Network) - A day after pulling out of the Olympics, Maria Sharapova announced she will also sit out the U.S. Open due to torn tendons in her shoulder.

Sharapova injured her right shoulder Wednesday night during her second-round match with Poland's Marta Domachowska at the Rogers Cup tennis event, a match in which Sharapova double-faulted 17 times.

A day later, Sharapova posted a message on her personal Web site.

"After yesterday's match I knew there was something seriously wrong with my shoulder," she said. "After taking a few different exams and MRIs this morning, the doctors found two small tears in the tendons of my shoulder."

In another posting on her Web site Friday, Sharapova confirmed that she probably will not need surgery but will me out for two to three months.

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

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

The 21-year-old superstar is a winner of three tournaments this year.

The Olympic tennis tournament begins August 11, and the U.S. Open starts on August 25.