Mattison sustained an ankle injury during Sunday's game at Las Vegas, Alec Lewis of The Athletic reports.
It's been a rough injury day for the Vikings, who have lost top wide receiver Justin Jefferson (chest), starting right tackle Brian O'Neill (ankle) and now their No. 1 running back. Mattison got injured on the team's first offensive play of the second half, and if he's unable to reenter the contest, he'll end Week 14 with 10 carries for 66 yards. Ty Chandler took over Minnesota's backfield after Mattison's departure.