Once upon a time, long, long ago, a Vikings safety intercepted a pass and raced 81 yards for the final rollick in a 34-6 victory at St. Louis in Mike Zimmer’s head coaching debut.

“Yeah,” said the safety, Harrison Smith, “that does seem like a long time ago.”

It was 18 days ago. Honest.

It might also go down as one of the dreariest 18-day stretches in franchise history. So it was only fitting when the Vikings had to move Wednesday’s walk-through practice indoors because of gloomy weather the team wasn’t anticipating.

“We got up this morning and expected the sun to be out,” Zimmer said. “But it’s still a good day.”

If you say so.

Yes, the Vikings are 1-2 and only a game out of first place in the NFC North. But the news from Winter Park is mired in a two-week tailspin that’s free-falling toward Sunday’s game against a Falcons team coming off a 42-point victory and 10 days of rest.

“Right now, a win would change everything,” Smith said. “A win and all the distractions go away. It makes everybody start feeling a little better.”

That would be some healing power. After all, in the past two weeks, the Vikings have lost their identity (Adrian Peterson), their running game, their quarterback, their right guard, their top tight end and the possibility of their top deep threat returning from suspension.

Quarterback Matt Cassel (foot) and right guard Brandon Fusco (pectoral) were placed on season-ending injured reserve Wednesday. Tight end Kyle Rudolph had sports hernia surgery Tuesday and could return in six weeks, which actually constitutes good news at Winter Park these days.

“We feel bad for them,” Zimmer said, “but we go on about what our business is.”

But even a veteran NFL coach such as Zimmer admits he couldn’t have imagined that he’d be entering his fourth game without Peterson, Cassel, Rudolph, Fusco and Jerome Simpson, whose continuing legal problems got him released last Friday, three days before he was eligible to return from his three-game suspension.

“I never envisioned that,” Zimmer said. “But it’s part of football. Last year in Cincinnati, we lost our best defensive tackle, our best corner, one of our best linebackers, our very good defensive end. Things happen in the NFL, so this is a survival-of-the-fittest game.”

The Bengals, with Zimmer as defensive coordinator, reached the playoffs last year for the third consecutive season. The Vikings, meanwhile, could be pressed just to avoid double-digit losses for the fourth time in five seasons.

“We’re only 1-2,” Smith said. “So all is not lost.”

Yeah, but the Vikings haven’t scored a touchdown in nearly 116 minutes. They haven’t had a takeaway in more than 122 minutes. And they’ve lost back-to-back games by a combined 34 points.

Their leading tackler the past six years (Chad Greenway) has two broken body parts (rib, hand) and didn’t practice Wednesday. Two other key defenders — No. 3 cornerback Josh Robinson (hamstring) and starting nose tackle Linval Joseph (shoulder) — also didn’t practice, while Smith (knee) was limited.

Meanwhile, roughly 38 percent of the $66 million in cap space devoted to offensive players is either sidelined because of injury or, in Peterson’s case, on a special exempt list while he faces child abuse charges in Texas. And two of the injured players — Fusco and Rudolph — recently signed five-year deals worth a combined $61.5 million.

So things aren’t looking real promising. A loss to the Falcons, who are favored by three points, would mark the 10th 1-3 start in franchise history. Eight of the first nine 1-3 starts ended with the Vikings missing the playoffs.

And now into the storm comes rookie quarterback Teddy Bridgewater to make his first NFL start after showing admirable poise for nearly three quarters in New Orleans.

That’s some pressure, eh kid?

“There’s no pressure on me, and it’s not about me,” the first-round draft pick said. “It takes a team effort to win football games.”

Of course, the question now is whether the Vikings have enough of a team left to accomplish that.