Pirates minor leaguer Duke Welker had Tommy John ligament replacement surgery on his right elbow Thursday, the Pirates announced today.
Physician James Andrews performed the procedure.
Welker, 28, had not pitched since May 3, when he allowed two runs on two hits and two walks in two-thirds of an inning while with Class AAA Indianapolis. He went on the minor league disabled list two days later.
Welker became the latest in a series of professional pitchers to have the procedure, which involves replacing the damaged ulnar collateral ligament in the elbow with a tendon from another part of the body. Recovery takes roughly a year.
Welker throws hard, and studies have shown that pitchers capable of higher velocity put more stress on their elbows. In recent years, Jose Fernandez, Matt Harvey and Stephen Strasburg, all hard throwers, have had the surgery.
The Pirates drafted Welker in the second round in 2007. They sent him to the Minnesota Twins to complete the Justin Morneau trade last fall but reacquired him a month later.
Also today, right-hander Vin Mazzaro cleared outright waivers and accepted his assignment to Indianapolis. The Pirates designated Mazzaro for assignment May 26. Mazzaro, 27, allowed four runs in 101/3 innings with the Pirates this season. He was designated for assignment for the second time, the other coming just before opening day.
Bill Brink: email@example.com and Twitter @BrinkPG.