Colts starting running back Vick Ballard will miss the rest of the season with a torn anterior cruciate ligament in his right knee.
Coach Chuck Pagano said Friday that Ballard was hurt making a cut in practice Thursday.
Former New York Giants star Ahmad Bradshaw is expected to start Sunday against Miami. The Colts (1-0) also promoted rookie Kerwynn Williams, their seventh-round draft pick, from the practice squad to the active roster.
Ballard was Indy's top rusher in 2012. The rookie ran for 814 yards and two touchdowns but was best remembered for making the diving, twisting TD he scored on a 16-yard TD pass to beat Tennessee in overtime. Last week, Ballard ran 13 times for 63 yards and was 6 for 6 on blitz pickups.