Vikings did not know Erin Henderson had a concussion until Wednesday
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EDEN PRAIRIE, Minn. -- Minnesota Vikings linebacker Erin Henderson sat out practice for the second consecutive day because of a concussion suffered in last Sunday's loss at Indianapolis.
Vikings coach Leslie Frazier said Henderson went through some concussion tests Thursday afternoon, but said there are more tests that must be done before the starting weak-side linebacker can get back on the field.
How he does in those tests will determine if Henderson can practice Friday.
Frazier said there were "no indications" on Sunday, Monday or Tuesday that Henderson had suffered a concussion. But Henderson realized something was wrong when he came out for practice Wednesday and, "did not feel right," according to Frazier.
It was at that point the Vikings put Henderson through the concussion protocol.
"You like to know as soon as possible, so you can go ahead and begin to do the tests that are necessary to determine whether or not it's a concussion and where the player is," Frazier said. "But in this case, we couldn't do that so you have to do it when you find out."
Henderson would be replaced by Marvin Mitchell if he can't play Sunday against the San Francisco 49ers. Jasper Brinkley, who normally comes out in nickel situations, would play alongside Chad Greenway on passing downs, if Henderson is unable to go. Frazier expressed his confidence in Brinkley's ability to play in the nickel defense.
Mitchell replaced Henderson briefly in the fourth quarter against the Colts but Henderson was able to return.
Henderson was at fault on Reggie Wayne's 30-yard touchdown reception late in the first half last weekend, but he also finished with a team-leading 12 tackles with one sack and three tackles for a loss.
"He played an outstanding ball game," Vikings defensive coordinator Alan Williams said. "That doesn't take away the touchdown that happened but he had a few tackles for a loss, he was in there on the sack, he was playing an outstanding football game, doing well, doing extremely well."
There were no changes to San Francisco's injury report on Thursday. Running back Brandon Jacobs (knee) did not participate, receiver Ted Ginn (ankle) was limited and punter Andy Lee (hand) was a full participant.