EDEN PRAIRIE — Minnesota Vikings linebacker Erin Henderson will miss the game against San Francisco today because of a concussion.

Henderson was injured last weekend in Indianapolis. But symptoms did not start showing until the middle of this week. The Vikings kept Henderson out of practice all week while he eases his way back.

His loss is a big one for a young and rebuilding Vikings defense. Henderson has been remaining in the game in passing situations as part of the nickel defense, and his absence will put more responsibility on middle linebacker Jasper Brinkley in the passing game. Brinkley is considered much better as a run defender.

Marvin Mitchell will start in Henderson’s place. Mitchell is just now recovering fully from an ankle injury that has bothered him since the preseason