"It'll be a week-to-week thing," Fisher said, per ESPN.com. "Zac could get 25 carries this week. We had some things in early this week. It was working so we decided to stay with 'Mase.' It's nothing that Zac has done or hasn't done. He's been a little banged up the last couple of weeks, but obviously he's an outstanding runner as well. We clearly have significant depth there at the position."
Stacy has been battling calf and ankle injuries in recent weeks and hasn't looked like the workhorse he was last season.
Mason wasn't involved in the passing game or asked to block -- both of which he struggled with during the preseason. Still, he looked like the most promising runner of the group this season.