It's a sore calf. Nothing serious. That's the official word from Vikings head coach Leslie Frazier on why star running back Adrian Peterson wasn't seen at the start of practice Wednesday afternoon at Winter Park. Frazier said Peterson took a kick to the calf at some point during Sunday's loss to Detroit and was still experiencing a bit of soreness. So as a precaution Peterson was held out of Wednesday's drills. He should be clear to practice Thursday and will play Sunday at Kansas City.

"We'll give him a chance to recover another day," Frazier said. "He'll be fine tomorrow."

As for linebacker E.J. Henderson, he missed Wednesday's practice to rest a sore left knee which has been giving him some trouble during the early season. Henderson will likely be ready to play Sunday though Frazier said he wasn't certain whether the veteran linebacker would practice much if at all on Thursday.

Injury report update: Tight end Jim Kleinsasser (elbow) and safety Tyrell Johnson (hip) were both listed as limited participants for Wednesday's practice. Other Vikings who were listed on the injury report but still participated fully Wednesday were cornerbacks Asher Allen (toe) and Chris Cook (groin) and defensive tackle Kevin Williams (foot).