Mason (ankle) has been ruled out for Thursday's game against the Lions.
Mason was unable to practice all week due to an ankle injury he sustained during the Vikings' 16-13 win over the Giants on Sunday. That leaves Aaron Jones as Minnesota's clear RB1 for Christmas Day, and Zavier Scott and Ty Chandler will step into larger rotational roles in the backfield in Mason's absence. Week 18 against the Packers on Sunday, Jan. 4 is Mason's last opportunity to play this season, given that the Vikings have been eliminated from playoff contention.