Mack had 10 carries for 55 yards during Thursday's preseason win against the 49ers.
After starting the Texans' first two exhibitions, Mack didn't take the field until the second half of preseason Week 3, yielding the start to rookie fourth-round pick Dameon Pierce (six rushes for 37 yards and one TD). Rex Burkhead also got run in the first half en route to 11 touches for 31 yards from scrimmage. It's unclear if this signifies a change in the pecking order of Houston's backfield, and it also should be noted Mack's healthy 5.5 YPC occurred against San Francisco's reserve defense. In any case, the trio seems to all be safe bets to make the Texans' initial active roster, as Dare Ogunbowale and Royce Freeman earned their touches in the third and fourth quarters Thursday.