The Minnesota Vikings' backfield is already taking a hit after an impressive season-opening victory over the Green Bay Packers.

Minnesota placed running back Jordan Mason on injured reserve Wednesday and signed DeeJay Dallas from the practice squad to the active roster, the team announced.

According to NFL Network's Ian Rapoport, Mason suffered a small fracture in his thumb that has since been repaired. Head coach Kevin O'Connell indicated Mason should be able to return relatively quickly, but his placement on short-term IR will keep him out for at least the next four games.

This story will be updated.ÂÂ