The loss of starting LB Erin Henderson to a concussion will cause Vikings' defensive coaches to shuffle the linebacker unit around for Sunday's game against the 49ers.

Losing Henderson is a big blow to the defense.

 “He's been doing a good job for us," coach Leslie Frazier. "We'll miss him. There's no question about it. But it gives someone else an opportunity. Marvin Mitchell will get a chance now."

Henderson's versatility will be missed. He is an every down linebacker who would stay in during nickel situations, while MLB Jasper Brinkley would be replaced by a cornerback. On Sunday, Brinkley will stay on the field in the nickel and Mitchell will come off.

Frazier has confidence Mitchell will be prepared. He knows he some catching up to do, especially since Mitchell is coming off a high ankle sprain that kept him off the field the first two games.

"What he'll miss is the speed of the game, this being his first week back," Frazier said. "That'll be an adjustment for him. Hopefully it won't take him a lot of plays to adjust to that part of it."

Frazier said rookie LB Audie Cole will see some action Sunday. Cole impressed fans during the preseason, registering two interceptions in one preseason game.

“I’m excited and I’ve been waiting for this opportunity,” said Cole. “I’ve got to make the most of it and stay up.”

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