Paul Hamm's comeback just got a little tougher.

The Olympic champion gymnast said Monday that he has a torn labrum in his right shoulder and will have surgery this week. He had hoped to return to competition for the first time since 2008 at next month's Winter Cup, a U.S. ranking meet.

"This is extremely disappointing since I have come so far and was preparing to compete in February," Hamm said in a statement through his agent. "I fully intend to rehab my shoulder with the goal of making the team and competing in the London Olympics."

Hamm won the all-around gold at the Athens Games in 2004, the first — and so far — only American man to win the Olympic title. He took 2½ years off to get his degree at Ohio State, then returned with twin brother Morgan in hopes of competing in Beijing.

Despite the time off, Hamm established himself as a serious threat for gold with convincing wins at Winter Cup and the American Cup in 2008. He was on his way to winning the U.S. title when he broke a bone in his hand at the national championships two months before Beijing.

He earned a spot on the Olympic team, but the hand and an injured shoulder forced him to withdraw a few weeks before the games.

Hamm's gymnastics career seemed to be over when he moved to Chicago and took a job as a finance trader. But he quit his job and started training full time in July.

"Though I am upset that I will not have the opportunity to (compete at Winter Cup) ... and may not be able to compete at the Visa Championships this summer, I have to be optimistic," Hamm said, "and remember that I am still on track to be fully prepared for 2012."