On Sunday afternoon, as the Vikings closed out their fourth win in five November games with one of the best drives of Kirk Cousins' time in Minnesota, the Broncos were preparing to kick off in Denver under circumstances no team hopes it will have to experience.

All four of the Broncos' quarterbacks were placed on the COVID-19 reserve list in advance of their game against the Saints. Jeff Driskell tested positive and the other three passers — starter Drew Lock and backups Blake Bortles and Brett Rypien — were put into testing protocol as close contacts, after reportedly attending a position group meeting in which none of the players was properly wearing masks or adhering to social distancing protocols.

What followed was both a cautionary tale and an exercise in the absurd: Practice-squad receiver Kendall Hinton started at quarterback, completing just one of his nine passes for 13 yards while throwing two interceptions in a game Denver lost 31-3.

It delivered a sharp reminder that even the most-maligned NFL quarterbacks aren't easily replaced on short notice, and returned to prominence an idea that Cousins' agent, Mike McCartney, had talked about publicly this summer: a "quarantine quarterback" who practices separately from the rest of the team in the event the rest of the team's QBs are unavailable because of COVID-19.

Teams such as the Eagles and Bills have used the idea this season, but Vikings coach Mike Zimmer said this week his team hasn't thought seriously about it since exploring the possibility this summer. Still, the events in Denver provided a reminder of how quickly a team's fortunes could change if one of its smallest — and arguably most important — position groups is affected by the coronavirus.

"Our staff has gone to tremendous lengths to avoid those circumstances from happening," Cousins said Wednesday. "We've already moved our meeting room two separate times, so we're in our third meeting room. Obviously masks, obviously six feet apart. There are basically mask police in our building who are opening doors in meetings and seeing if everybody has their masks on, and if you don't have your mask on, you are being chastised pretty strongly, so it's being monitored from the moment you step in the building until the moment you leave."

Players also wear proximity tracers that will flash red if they are too close to one another.

"It's just been beaten into us since the end of July, as to the habits we have to have," Cousins added. "To this point, it's been effective. We've got another month-plus, hopefully, and we've got to be very vigilant to keep at it."

The Vikings' four QBs (Cousins, Sean Mannion and practice-squad players Jake Browning and Nate Stanley) have moved from their normal position room to the tight end room at the team's practice facility, before shifting to a larger meeting room where "we've got tons of space," Mannion said.

The league had closed all team facilities Monday and Tuesday after the Thanksgiving holiday, and has put all teams in intensive protocols the rest of the season, meaning meetings have to be conducted virtually or with a league-approved plan if they're happening in person.

"There's been a few times when we've had to hop on Microsoft Teams for a meeting, but in terms of the way we work with each other to preparing everything, that's all been the same as it ever was," Mannion said. "So I think it's just kind of been a year of making adjustments. I think we've done a good job of that so far. Really I think you're so focused on the game plan, so focused on football that, they tell you where to be, where to log on and you're there and that's kind of all there is to it."

On a conference call Wednesday, shortly before the Ravens and Steelers were set to play a game that had been delayed since last Thursday because of a COVID-19 outbreak for Baltimore, Commissioner Roger Goodell reiterated the league will postpone games only for health reasons, not for competitive ones. That means any team that finds itself in the Broncos' situation will have to manage.

Dr. Allen Sills, the NFL's chief medical officer, said the league hasn't ruled out the idea of local bubbles for the playoffs, though Goodell said he can't see the league going to a bubble "in the way the media is talking about it," which likely meant putting teams in a central location the way the NHL, NBA and MLB did for their postseasons.

If the Vikings ever needed an emergency quarterback, Zimmer said, Adam Thielen would be the first option, followed by Kyle Rudolph (who would have done the job if the Vikings had needed one on Sunday with Thielen still on the COVID-19 reserve list). During training camp, Zimmer said, the Vikings take a day to work on what they would do if they didn't have an available quarterback. "Then we repeat it, typically on Saturdays," he added.

The coach remained skeptical of the quarantine QB idea, saying, "Quite honestly, if a guy isn't practicing, he's probably not going to play very good anyway."

With Thielen returning on Wednesday, the Vikings started their Week 13 preparation with no players on the COVID-19 reserve list. They're moving forward with a belief they can guard against a rise in cases if they continue what they're doing.

"We'll just keep being really careful with our protocols and being smart with the masks and all of that," Zimmer said. "What happened to [the Broncos], from what I understand, was close contact. We've been really diligent about that, guys wearing masks and those types of things."