After two days of slight optimism regarding Minnesota Vikings running back Adrian Peterson and his ankle injury, said optimism has been dissipated. According to the Pioneer Press, Peterson has officially been ruled out for Sunday's game against the Denver Broncos by head coach Leslie Frazier.
Peterson was nowhere to be seen at practice on Friday, which is a change from previous days. He didn't test his ankle sprain on Wednesday, but had expressed confidence in the fact that he thought he'd be playing on Sunday. When Thursday rolled around, Peterson was saying that his ankle felt good running on it, and again expressed confidence that he'd play.
Peterson said he was expecting a decision on Saturday, so there was either a setback late Thursday or early Friday, or perhaps the team just decided that it was too close for comfort, regardless. With the team not competing for the playoffs at this point, there's no reason to risk your feature running back.