Roberts slated for Thursday surgery on hamstring

BALTIMORE -- Orioles second baseman Brian Roberts will undergo right hamstring surgery on Thursday in Dallas and is expected to be out about six more weeks, further delaying his comeback hopes this season.

Roberts is scheduled to be operated on by Dr. Daniel Cooper at the Carrell Clinic. Baltimore said the recovery time is expected to be about six weeks, and Roberts will report to Sarasota, Fla., afterwards.

"He's determined. He's determined to get it right and get back," manager Buck Showalter said following Wednesday's 5-3 win over the Royals. "He's very frustrated by it, but he's determined. He's had to fight back from a lot of things. A lot of guys would have pulled the dirt in, but he's not going to do it. He thinks we've got a chance to be competitive this year and he wants to be a part of it, because he thinks he can help us, and so do I."

The surgical procedure is called a semitendinosus release, involving one of the three muscles that make up the hamstring itself.

Roberts sustained the injury while sliding during a game against the Tampa Bay Rays on April 4, and he needed to be helped off the field. The Orioles placed him on the 15-day disabled list.

Injuries have plagued the former All-Star the last few years. Roberts has played in just 118 games since the start of the 2010 season.