The Texans released Mack from the practice squad Monday, DJ Bien-Aime of ESPN.com reports.
Mack was cut from the practice squad to make room for Chris Conley. Mack once appeared to be a candidate to win the starting role in Houston's backfield, but he now may have to search for a depth opportunity elsewhere in the league. Rookie fourth-round pick Dameon Pierce looks primed to start Week 1 against the Colts for the Texans.