Shortstop Mychal Givens, the Orioles second-round draft pick last June, underwent surgery on his left thumb last week and will miss the rest of this season. It was expected that Givens would be out several weeks due to the procedure. Now the plan is for him to begin some rehab around mid August and likely go to the O's instructional league workouts in September. The 20-year-old Givens was playing at extended spring training this year before being sent to the Delmarva Shorebirds. He got into seven games with Delmarva between May 25 and June 1, batting .222-0-4 with four hits in 22 at bats. He injured the thumb diving into a base June 1 in a game vs. Greensboro and has been on Delmarva's disabled list since. Givens was taken with the 54th overall selection last year out of Plant High in Tampa was he was a shortstop and pitcher.