HOUSTON — Paul Hamm's stay at the top of the U.S. championships might be a short one.

Hamm said he might not compete Saturday after injuring his first hand in the last few seconds of his parallel bars routine, his final event of the night Thursday. As Hamm was flipping to do work on one bar, his right fingers caught on the rail and were jammed to the side. He fell off, and immediately grabbed his wrist as he grimaced.

"I heard a small popping sound in the joint," said Hamm, who will have X-rays Friday morning. "This is not something that will make me sit out of the Olympics, but it might make me sit for Saturday. If it's something very little, I'll compete Saturday. If I think it is something worse, I'll hold off until trials.

"I will not beat up my body and cause more damage just to get to the trials."

Even with the injury, Hamm still had a commanding lead. His score of 93.450 was more than three points ahead of Joseph Hagerty, who had 89.750.

The Olympic trials are June 19-22 in Philadelphia, and Hamm is considered the only lock to make the team — even if he's not at trials.