San Francisco 49ers receiver Derrick Hamilton tore a ligament in his left knee during a workout on Wednesday. The injury could potentially sideline him for the entire upcoming season. The Niner?s third round pick from last year?s draft will have surgery next week according to S.F coach Mike Nolan. "Derrick has worked very hard in the offseason and minicamp to improve, and we hope his recovery allows him to contribute at some point in 2005," Nolan said.