Colts' Marlon Mack: Impressive in preseason debut

Mack had five carries for 45 yards and two receptions for 14 yards in Saturday's preseason loss at Dallas.

Mack showed a spark in his first preseason game as he'd missed Indy's first game with a shoulder injury. While likely stuck behind Frank Gore and Robert Turbin, the fourth-round rookie could make a case for a change-of-pace role with another strong outing or two this preseason. He may have the most upside of any of the backups if Gore were to get hurt.