The Vikings downgraded starting running back Adrian Peterson to questionable for Sunday's game against the Detroit Lions because of an illness. He remains likely to play.

Peterson was listed as probable on Friday's injury report as he dealt with a finger injury. This illness was not disclosed on the report, which suggests Peterson became ill Saturday. Per NFL rules, the Vikings have to disclose his illness and make an appropriate change to the final injury report.

If Peterson is unable to play, Matt Asiata and Jerick McKinnon would split snaps at the position. Last season, with Peterson out of the mix, Asiata handled short-yardage and goal-line work while McKinnon got the bulk of the carries on early downs.

This development comes a week after the Vikings were without starting defensive end Everson Griffen for their 16-10 win over the Chiefs because he became ill the morning of that game. Griffen checked into Hennepin County Medical Center before the game and underwent testing there. He returned to practice Thursday and is expected to play against the Lions.

MATT VENSEL