Roberts to undergo hamstring surgery Thursday

Orioles second baseman Brian Roberts, limited to 118 games over the past four seasons because of various injuries, will undergo surgery Thursday on his right hamstring. Roberts, 35, will undergo a procedure to repair one of the muscles in his hamstring - it's a "semitendinosus release" - and the recovery time is expected to be approximately six weeks. Dr. Daniel Cooper will perform the surgery at Carrell Clinic in Dallas. Roberts will eventually report to Sarasota to begin his rehabilitation. The Orioles can transfer Roberts to the 60-day disabled list if they need to clear a spot on the 40-man roster. Roberts went on the 15-day DL on April 5 after injuring his hamstring the previous day while sliding into second base in a game against the Tampa Bay Rays at Tropicana Field. The injury was listed as a ruptured tendon behind the knee. Roberts had been running and throwing in Sarasota, but the discomfort returned while he attempted to take light batting practice. Cooper also performed surgery on Evan Longoria's hamstring prior to the 2012 season. Roberts has been in contact with the Rays third baseman, which led to his appointment with Cooper. Ryan Flaherty and Alexi Casilla continue to platoon at second base for the Orioles in Roberts' absence. Roberts no longer is bothered by concussion symptoms, but he had surgery in August to repair a torn labrum in his hip, and another surgery in December for a sports hernia. Roberts is in the final year of his contract, which pays him $10 million in 2013.