If the Vikings miss the playoffs by one game, the enduring image from their 2020 season will not be Dalvin Cook speeding past tacklers, Adam Thielen one-handing touchdowns or Justin Jefferson dancing in the end zone.

The defining moment for this team will be a reserve defensive back playing matador on a long touchdown run in a game the Vikings probably had to win.

Chris Jones, a 6-0, 200-pound cornerback, allowed Cowboys backup running back Tony Pollard to run past him without attempting to make a tackle. Pollard went 42 yards for an embarrassingly easy touchdown early in the fourth quarter, and the Cowboys produced a game-winning touchdown in the final two minutes to take a 31-28 victory at U.S. Bank Stadium.

A franchise that will never forget Drew Pearson’s “Push Off’’ now can try to forget Jones’ “Back Off.’’

Jones seemed to make what football players call “a business decision,” and in this case it means Jones may need to find a new business.

Sunday began with hope for the Vikings. The Saints, one of the teams the Vikings are chasing, are without star quarterback Drew Brees indefinitely. They started former special-teamer Taysom Hill at quarterback on Sunday. The Vikings were at home, riding a three-game winning streak and playing a 2-7 Cowboys team playing its backup quarterback.

Then Hill led the Saints to an easy victory over Atlanta, and the Vikings squandered exceptional performances from Cook, Thielen, Jefferson and Kirk Cousins.

It’s hard to lose a game when your running back produces 160 yards and a touchdown, your two best receivers produce 211 yards and three touchdowns and your quarterback passes for 314 yards and no interceptions. But the Vikings found a way because Jones refused to get in the way.

Now the Vikings are 4-6, have games at Tampa Bay and New Orleans remaining, and can afford maybe one loss the rest of the way if they’re going to make the playoffs.

On Pollard’s touchdown run, he took a handoff to the right, then burst upfield. Jones was playing outside and was the only Viking who had a chance to stop him. Jones was unblocked but would not have made the stop if this had been flag football.

One of the downsides of media not being in the locker room after games because of the pandemic is that reporters didn’t get a chance to ask Jones for an explanation. The Vikings made four people available via Zoom — coach Mike Zimmer, Cousins, Cook and linebacker Eric Kendricks.

Maybe Jones has a good excuse for avoiding contact. Maybe he’s hurt. Maybe he abhors violence. We don’t know, and we may never know.

What we do know is this: There are two things you shouldn’t do if you want to make the NFL playoffs — start 1-5, and ignore the “tackle” part of “tackle football.’’

The closest a Vikings came to addressing the play during the postgame interviews was Zimmer saying, “We weren’t very good in the red zone, missed a tackle on a long run.”

To be fair, most coaches and players can’t see everything that happens on the field. “I need to watch the film” is sometimes a cop-out and sometimes an excuse, but sometimes it is true.

On Sunday, Cook, Thielen and Cousins all took nasty hits and kept on playing, and playing well. What will they and their defensive teammates think once they realize that Jones became a conscientious objector during one of the most important plays of the season?

“It’s the NFL. You’ve got to come to play every week,” Kendricks said, speaking generally and not about Jones. “You make one little mistake and you see two of their runs go longer. We’ve got to be perfect every single time we go out there, or close to it.”

NFL players are professionals. They know how to deal with bad calls, bad plays, bad losses. What they have trouble stomaching is a lack of effort from teammates.

What will they think when they get a good look at Jones doing all he can to reduce violence in America?