The Mets said the 34-year-old left-hander was operated on Tuesday at the Hospital for Special Surgery. Mets medical director David Altchek repaired a tear in the capsule in the front of his left shoulder. The team said the two-time Cy Young Award winner will be hospitalized overnight.
Santana is likely to miss the entire season for the second time in three years. He had surgery on Sept. 14, 2010, to repair tears in the front and bottom of the shoulder's anterior capsule and did not make it back to the major leagues until last April 5.
New York still owes Santana $31 million from his $137.5 million, six-year contract. General manager Sandy Alderson said the remainder of the contract is not covered by insurance.