Dennison was with the Vikings for the last two seasons, and has also coached with the Broncos, Texans, and Ravens. He has been working in the NFL since the mid-1990s.
The NFL recently announced new protocols for staff and players; tier 1 staff, which includes coaches, must receive the COVID-19 vaccine or present the league with a valid religious or medical reason for not getting it.
A coach with the New England Patriots, Cole Popovich, will also not be returning for the 2021 season in a decision related to the COVID-19 vaccine, according to ESPN.
Players are not considered tier 1; however, if a player is not vaccinated, they will be subject to more COVID-19 testing, social distancing requirements, and travel restrictions.
The league has also informed all 32 teams that COVID-19 outbreaks among unvaccinated players could ultimately result in forfeiting a game.