The Facts: Minnesota Vikings head coach Leslie Frazier announced tight end John Carlson is being evaluated for a concussion. If he is confirmed to have sustained a concussion, it would be Carlson's second in eight games and the fourth in his career dating back to his college years at Notre Dame. His most recent concussion occurred in January 2011 as a member of the Seattle Seahawks. Carlson was knocked unconscious during the NFC playoffs versus the Chicago Bears and was hospitalized for the night. A shoulder injury cost him the entire 2011 season. He signed a five-year, $25M deal with the Vikings this offseason.

Diehards Line:Carlson hasn't been heavily involved in the Vikings pass offense except as a blocker. We expect the Vikings to exercise caution with him, given his concussion history.