OXNARD, Calif. (August 4, 2012) -- Dallas Cowboys rookie cornerback Morris Claiborne could miss at least a week with a sprained left knee.

Claiborne watched the team's walk-through practice Saturday morning standing by a coach. He says it's frustrating to miss more time.

The Cowboys drafted Claiborne with the sixth overall pick in April after trading up eight spots and giving up their second-round pick. He missed offseason workouts while recovering from wrist surgery, but is still expected to be a starter.

Claiborne got hurt toward the end of practice Wednesday, then got treatment the following day, an off day for the team. After trying to practice Friday, he came off the field and later had an MRI that revealed a sprained MCL.