Two-time Cy Young Award winner Johan Santana has suffered a probable re-tear of the anterior capsule in his left shoulder and a repeat surgery is a "strong possibility," New York Mets general manager Sandy Alderson said Thursday.

Santana needed 19 months to throw a major league pitch after the first procedure, which had been performed on fewer than a dozen pitchers in major league history.

Now, he likely would need to overcome the surgery twice, this time at age 34, in order to return to pitching.

Santana is in the final guaranteed season of a six-year, $137.5 million deal with the club. There is $31 million still owed on the contract, all of which is not insured.

Santana was examined in New York on Wednesday by team doctor David Altchek, who performed the original Sept. 2, 2010, procedure. An MRI revealed a probable re-tear. At the request of Santana's agent, Altchek consulted with renowned doctors James Andrews and Lewis Yocum. Both confirmed the probable diagnosis of the re-tear of the anterior capsule, Alderson said.

Santana will remain in New York this weekend to deliberate before committing to surgery.

"If this diagnosis proves to be correct, I think in all likelihood Johan will be lost to the Mets for the season," Alderson said.