After refusing to receive a vaccine for COVID-19, Rick Dennison is out as a Minnesota Vikings assistant coach, sources told ESPN on Friday.

Dennison, who had served as the Vikings' offensive line coach/run game coordinator the past two seasons, is believed to be the first NFL position coach to part ways with his team after choosing not to receive a vaccine.

The vaccine is required for all Tier 1 staff, including coaches, front-office executives, equipment managers and scouts. Players are not required to receive the COVID-19 vaccine but will face strict protocols during training camp and throughout the season that vaccinated players will be able to forgo.

In a memo released by the league earlier this summer, the NFL said any unvaccinated Tier 1 staff member must provide a valid religious or medical reason for not receiving the vaccine. Losing Tier 1 status prohibits coaches from being on the field and in meeting rooms and having direct interactions with players.