Sendejo's suspension stems from his hit on Baltimore Ravens wide receiver Mike Wallace during the first quarter of Sunday's game, which resulted in Wallace leaving the game with a concussion. Sendejo made helmet contact with Wallace's helmet, which came off in the collision. He was flagged 15 yards for unnecessary roughness on the play.
Sendejo filed for an appeal, but the NFL announced on Tuesday that appeals officer Derrick Brooks upheld the one-game suspension.
Jon Runyan, NFL Vice President of Football Operations, announced Sendejo violated the rule which bars players from "using any part of a player's helmet or facemask to butt, spear, or ram an opponent violently or unnecessarily."
"Obviously, there was no intent to hurt Mike," Sendejo told reporters Sunday. "He was here [in Minnesota] for a year. I got to know him. Hopefully, he recovers and can play next week."
In his letter to Sendejo, Runyan wrote:
"The violation was flagrant and warrants a suspension because it could have been avoided, was violently directed at the head and neck area and unreasonably placed both you and an opposing player at risk of serious injury."