Vikes looking into sudden injury to Simpson's left leg

EDEN PRAIRIE (AP) -- The Minnesota Vikings were trying to determine Monday why wide receiver Jerome Simpson woke up with numbness and weakness in his lower left leg that hindered him in the game against Tennessee.

Coach Leslie Frazier said Simpson was undergoing MRI tests. Simpson played in parts of Minnesota's 30-7 win, but he didn't catch any passes. He had trouble pushing off because of the injury, which Frazier said could also be connected to his back.

"This was completely new for him and so as you can imagine, it scared him, had him alarmed," Frazier said. The coach added, though, that the Vikings aren't bracing for a long-term absence.

"We shouldn't be afraid to the point where we're going to lose him for a long period of time, but everything is not conclusive," Frazier said.

The Vikings tweeted Monday a link from their official account to a photo of Simpson "getting some serious air" with a leap he made on his way out of the tunnel during pregame player introductions. But Simpson was otherwise unable to use his explosiveness on the field.

"We were hoping that as time went on he'd regain that feeling over the course of the game, because in talking with the doctor they felt like that was possible," Frazier said. "It did get a little bit better but not to the point where he felt completely comfortable."

Also, running back Adrian Peterson suffered a mild sprain of his left ankle that he played through, finishing with 88 yards on 17 rushes. Frazier said the Vikings don't see "anything that will keep him from playing" on Sunday at Washington.

"When it's the same leg where you had the knee injury, I can see there being a little bit of doubt in your mind about what is going to happen next but to his credit once again, he kept himself together, got back on the field. He ran great," Frazier said.