Cook rushed the ball six times for 25 yards in Saturday's 9-3 preseason win over the Steelers.
Cook was unsurprisingly the first Buffalo running back on the field, but he was the only player to record a rushing attempt with the first-team offense on the field. That usage wasn't quite as significant because the Bills failed to approach the goal line -- the most likely spot for Cook to lose work during the regular season -- but it's at least some indication of the gap that he has built as the Bills' lead back over Ty Johnson and Ray Davis.