NEW YORK — Yankees left-hander James Paxton had back surgery Wednesday and is expected to be sidelined until May or June.

New York said Dr. Andrew Dossett in Dallas performed a microscopic lumbar discectomy, in which a herniated disk is repaired, and removed a peridiscal cyst. The Yankees estimated Paxton's timeline to pitch in a major league game is three to four months.

Paxton left his final regular-season start, at Texas in Sept. 27, after one inning with what the Yankees said was a tight left glute muscle. That ended Paxton's career-best streak of victories in 10 consecutive starts. He was 1-0 with a 3.46 ERA in three post-season starts, allowing five runs in 13 innings.

Paxton's injury weakens a Yankees rotation already missing right-hander Domingo Germán, who must serve the final 63 games of an 81-game suspension for violating Major League Baseball’s domestic violence policy. He is eligible to return June 5, barring any postponements.

After agreeing to a $324 million, nine-year contract. right-hander Gerrit Cole heads a rotation that includes righties Luis Severino and Masahiro Tanaka and lefty J.A. Happ. Lefty Jordan Montgomery, who returned in September from Tommy John surgery, is the most likely candidate to replace Paxton in the rotation at the start of the season.

Paxton's injury is the second for the Yankees, who start spring training next week. Switch-hitting centre fielder Aaron Hicks is not expected back until June or July following Tommy John surgery on his right elbow on Oct. 31.

New York placed a big league record 30 players on the injured list a total of 39 times last season, then overhauled its training and conditioning staff.

A 31-year-old left-hander, Paxton was a career-best 15-6 with a 3.82 ERA last season. He was 5-6 in July but started to reduce his percentage of fastballs and went on his streak.

He agreed last month to a $12.5 million, one-year contract and is eligible for free agency after the season.