TORONTO -- Right-hander Mike Pelfrey underwent surgery on Tuesday to clean up scar tissue in his right elbow that was causing pressure on his ulnar nerve, the Twins announced.
Pelfrey met with Dr. James Andrews for a second opinion on his elbow in Pensacola, Fla., on Monday, and Dr. Andrews performed the surgery on Tuesday. He's expected to be out two to four months.
Pelfrey had Tommy John surgery on his right elbow on May 1, 2012, which caused him to miss the rest of that season and led to the scar tissue buildup in his elbow that necessitated Tuesday's operation. But his ulnar collateral ligament is fine now, as the injury was related to the ulnar nerve.
Pelfrey began to feel numbness in his fingers during Spring Training but never notified the training staff, as it was something he'd dealt with earlier in his career without any issues.
He went on to post a 7.99 ERA in five starts with diminished velocity before going on the 15-day disabled list with a groin strain on May 2. He made two rehab starts with Triple-A Rochester before he began to feel what he thought was shoulder pain, but turned out to be related to the ulnar nerve in his elbow after he had both his shoulder and elbow checked out by Twins doctors in late May.
Pelfrey, 30, posted a 5.19 ERA in 29 starts in his return from Tommy John surgery last year, and the Twins were hopeful he'd bounce back this season after being another year removed from the surgery. He signed a two-year, $11 million deal in the offseason to remain in Minnesota.
Rhett Bollinger is a reporter for MLB.com. Read his blog, Bollinger Beat, and follow him on Twitter @RhettBollinger. This story was not subject to the approval of Major League Baseball or its clubs.