Vikings head coach Kevin O'Connell said after Sunday's 3-0 win over the Raiders that Nailor has entered the NFL's concussion protocol, Ben Goessling of the Minneapolis Star Tribune reports.
It's unclear when Nailor sustained the concussion, as he finished Sunday's game with two catches for 15 yards and his five targets on the day were third on the team behind T.J. Hockenson and K.J. Osborn. Nailor will have a shortened window to clear the league's five-step protocol as the Vikings face the Bengals on Dec. 16.