Buenos Aires, Argentina -- French Open runner-up Guillermo Coria is expected to be sidelined for up to three months after undergoing arthroscopic surgery on his right shoulder.

Coria had already withdrawn from the upcoming Olympic Games in Athens and now will most likely miss the U.S. Open, as the final Grand Slam event of the year gets underway on August 30.

"The doctors say I will be out for up to three months," Coria said on his website gcoria.com on Tuesday.

The world No. 3 Coria was forced to retire from his first-round match against Luis Horna during the Tennis Masters Canada event in Toronto two weeks ago and then pulled out of last week's Masters Series tournament in Cincinnati.

Coria was stunned by fellow Argentine Gaston Gaudio in the 2004 French Open final. Gaudio will also miss the Summer Games because of an injured right foot.