The Cowboys elevated Cook from the practice squad Saturday.
Cook joined the Cowboys' practice squad in late August, but he waited eight weeks to receive his first promotion to the roster ahead of game day. Though the four-time Pro Bowler is clearly on the downside of his career, Cook could have a chance to push for the No. 2 role in the backfield right away behind starter Rico Dowdle. Reserve backs Ezekiel Elliott (3.0 yards per carry) and Deuce Vaughn (2.9 yards per carry) have been woefully inefficient this season, and Vaughn has been a healthy inactive in both of Dallas' previous two games.