Matt Kemp underwent an hourlong operation Friday that revealed the condition of his left shoulder was worse than expected, raising doubts about whether he will be at full strength for the start of next season.

Kemp is believed to have torn his labrum crashing into a wall in Colorado on Aug. 28. He and the Dodgers were hoping the damage would be relatively minor and require nothing more than a cleanup, but Dr. Neal ElAttrache decided the labrum had to be repaired — that is, reattached to the socket.

The Dodgers issued a statement stating ElAttrache expects Kemp to be ready for opening day. The All-Star center fielder will begin physical therapy in seven to 10 days and is expected to start swinging a bat in early January, according to the team.

A team spokesman said the Dodgers would have no other comment on Kemp's status.

Earlier in the week, trainer Sue Falsone said Kemp could be sidelined for four months if he had a labral repair. "He wouldn't be far behind," she said. "He would have a fairly normal spring training."

First baseman Adrian Gonzalez underwent a similar procedure in October of 2010. He was limited to 11 games the following spring.

"I didn't have a lot of power in April, but I got hits and everything," Gonzalez said. "Once May rolled around, I felt pretty good."

Gonzalez hit only one home run that April for the Boston Red Sox, but he finished the season with 27.