NFL VP of Football Communications Michael Signora announced the news in a release, noting the hit was a violation of safety-related playing rules.
ESPN's Adam Schefter reported Tuesday that the ruling was upheld by the NFL.
Wallace was almost immediately ruled out for the rest of the game due to a concussion.
The aftermath of the hit was also graphic:
Sendejo was flagged for unnecessary roughness on the first-quarter play, although the league believed the hit required a harsher punishment.
"The violation was flagrant and warrants a suspension because it could have been avoided, was directly at the head and neck area and unreasonably placed both you and an opposing player at risk of serious injury," NFL VP of Football Operations Jon Runyan wrote in a letter to the Vikings safety, via Signora.
The 30-year-old has developed into a key player in the Minnesota defense, starting each game he has played over the past three seasons. He is currently tied for second on the team with 42 tackles on the year, while his ability to play in the box often leads to big hits like the one on Wallace.
His play has helped the Vikings rank in the top five in both yards and points allowed per game in 2017.
While Sendejo has the option to appeal, Jayron Kearse would likely fill in at safety after being limited to mostly special teams work this season.
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