Johan Santana is headed for shoulder surgery, making this the third straight year the high-priced New York Mets' ace will spend the offseason recovering from an operation.

The Mets said they anticipated Santana would be OK to resume throwing next spring. But left-hander acknowledged doctors told him it was "not a common injury" to his pitching shoulder, and Santana said the most important thing was for him to get healthy.

"Whether it's April, May, July, October," Santana said Friday. "Who knows? Time will tell."

An MRI exam on Thursday showed the two-time AL Cy Young Award winner has a torn anterior capsule on the front and bottom of his pitching shoulder. The 31-year-old Santana was 11-9 with a 2.98 ERA in 29 starts this season, and had pitched 199 innings.

Santana left his start a week ago Thursday in Atlanta after five innings because he felt tightness in his shoulder. He told manager Jerry Manuel he could keep pitching, but was taken out as a precaution. The Mets later announced he had a strained pectoral muscle and listed him as day-to-day.

"I didn't know the magnitude of the injury I had," Santana said before the Mets opened a series against Philadelphia. "I was told it's going to take time."

Santana said his injury was similar to one that Yankees catcher Jorge Posada was able to recover from. Santana said he was waiting for a second opinion from noted orthopedist Dr. James Andrews.

Santana said he'd prefer to have the surgery soon so he could begin his rehabilitation. He should be able to begin playing catch in January, he said doctors told him.

"I just have to recover and hope this will be the end of it," Santana said. "Get everything fixed."

That's been a tough goal for him to reach the last few years.

Santana's 2009 season was cut short by Sept. 1 surgery to remove bone chips from his left elbow.

In October 2008, he had arthroscopic surgery on torn cartilage in his left knee right after the season ended.

Santana has three seasons left on his $137.5 million, six-year contract.

"I feel he will fulfill those next three years," Mets general manager Omar Minaya said. "Hopefully, we'll have him back sooner than later."

Dillon Gee, who pitched well this week in his major league debut, will take Santana's spot Monday night against Pittsburgh. Manuel said the Mets will monitor Gee to see whether he remains in the rotation for the rest of the season.

The Mets have had their share of injury woes over the past several seasons.

All-Star outfielder Jason Bay, signed as a free agent last winter, still is recovering from a concussion on July 23. He was working out at Citi Field before Friday night's game and hoped he could return to the lineup before the season ends.

"If I have a chance to play, I'd like to do it," he said.

All-Star shortstop Jose Reyes, sidelined since Aug. 26 by a right oblique strain, was set to start against the Phillies.

The Mets, however, have slipped below .500 and faded from playoff contention, doomed by injuries and inconsistency.

"Unfortunately, we're in a cycle right now we wish we were not," Minaya said.