Righthander Humberto Sanchez had Tommy John surgery Wednesday, making him the fourth Yankees pitching prospect to have a significant elbow procedure since the conclusion of the 2006 season.

Sanchez, the organization’s No. 3 prospect, joined fellow righthanders J.B. Cox (eight), Chris Garcia (14) and Mark Melancon (15) on the disabled list.

Garcia had offseason surgery to reinforce a torn ligament, while Melancon had Tommy John surgery last November. Both are expected to miss the season. Cox also had elbow surgery–though not Tommy John–and is also expected to miss the season.

Another righthander, Joba Chamberlain (five), opened the season on the disabled list with a strained left hamstring and has yet to pitch. He’s expected back in a week or two.