SURPRISE, Ariz. -- Rangers right-handed pitching prospect Thomas Diamond is scheduled to undergo Tommy John elbow reconstruction surgery on Tuesday and is expected to miss the entire 2007 season.
The Rangers are expecting him to be at full strength in Spring Training next year.
"It's a setback," Rangers general manager Jon Daniels said. "But this injury has a high success rate. I expect him back but he's going to miss the season. You feel for Thomas. He worked hard this off-season.
The surgery to repair a torn ligament will be performed by Dr. James Andrews in Birmingham, Ala.
Diamond, the Rangers' first-round draft pick in 2004, has had elbow discomfort off and on since the Rangers' mini-camp in January and the condition flared up again after his one appearance in an exhibition game against the Seattle Mariners on March 6.
He allowed two runs in an inning of work and then underwent an MRI afterward. That's when the torn ligament was discovered.
"We were hoping the findings would be different based on where he had the initial discomfort," Daniels said. "This wasn't what the doctors expected. We didn't think it was serious until we got the MRI back."
Diamond was the Rangers' Minor League Pitcher of the Year in 2005 and was 12-5 with a 4.24 ERA in 27 starts at Double-A Frisco in 2006. He led the Texas League in strikeouts. He and Eric Hurley are considered the Rangers' top two Minor League pitching prospects.
T.R. Sullivan is a reporter for MLB.com.
This story was not subject to the approval of Major League Baseball or its clubs.