The supposedly desperate Vikings strolled into U.S. Bank Stadium on Sunday morning, confident they would make quick work of the Indianapolis Colts.

Adrian Peterson was back in the lineup, expected to give them an emotional lift and some semblance of a running game. The Colts were forced to start three rookie offensive linemen against one of the NFL’s most ferocious pass rushes. The Colts had Andrew Luck, but did anyone else scare them?

And their fans were fired up, even if simply because they were inside.

Then the game started, and was seemingly over a minute or two later.

The Colts took a 10-0 lead in the first quarter and stunned the Vikings and the crowd by increasing it to 17-0 in the second. When they made it 27-0 just before halftime, some of those fans thought it would be more enjoyable to walk out into subzero temperatures than sit inside and watch the rest.

The Colts cruised to a 34-6 victory, and the bewildering loss all but eliminated the sleepwalking, penalty-prone Vikings, now 7-7, from playoff contention.

“We just came out lackadaisical … like they were going to read [our] names, look at [our] stats and lay down for us,” cornerback Captain Munnerlyn said, adding, “To come out like this today, it definitely was embarrassing.”

In fact, it was arguably the most embarrassing loss of the Mike Zimmer era.

The first big blunder came after the Vikings, down 3-0, got a third-down stop near their goal line. But nose tackle Linval Joseph was flagged for illegally contacting the long snapper on a Colts field-goal try. The penalty gave the Colts a first down and they soon scored on a 1-yard run by Robert Turbin.

Midway through the second quarter, the Colts made it a three-score game after Luck chucked a 27-yard touchdown to tight end Erik Swoope, who ran right by veteran outside linebacker Chad Greenway on a go route.

The Vikings finally got something going offensively before halftime, but Peterson, fighting for a few more inches at the end of his only good run, coughed up the football at the 9. Colts safety Mike Adams snatched it up.

In his first game back from a knee injury, Peterson touched the ball seven times. The Vikings got him involved right away, handing it to him on their first play, and immediately followed it with a swing pass to the 31-year-old running back. But he rushed for only 22 yards in his first game since Sept. 18.

“He looked like Adrian at practice this week. You see the way he runs and hits the holes. I truly thought he was going to be a nice spark for us,” said tight end Kyle Rudolph. “You have points in your season that kind of propel you on five-, six-, seven-game win streaks. I thought today was going to be that day.”

But the offense, which had changed so much since Peterson last played, was predictably out of sync as the Vikings force-fed the rusty running back early on. They picked up only two first downs and gained 69 total yards in the first half.

It didn’t help that Zimmer’s defense couldn’t corral the Colts and did not sack Luck once. After Peterson’s fumble, they marched right back down the field to score again, with Turbin shaking loose of three Vikings defenders on his way into the end zone.

Then quarterback Sam Bradford was intercepted in Vikings territory and the Colts booted a field goal as the first half ended, mercifully, with the Vikings down 27 points and in need of the greatest comeback in team history.

“It didn’t go great early, and it kind of snowballed,” Bradford said. “The next thing you know, we’re down three or four scores and it’s … about as ugly as it gets.”

The second half started with a lost Bradford fumble, and Luck, who threw for 250 yards before taking a seat in the blowout, heaved a 50-yard touchdown pass to Colts wide receiver Phillip Dorsett early in the fourth quarter.

When the Vikings finally got on the board with a third-quarter field goal, making it 27-3, some fans mocked them with an exaggerated ovation. And despite being down 31 points, they had Kai Forbath kick another one in the fourth.

Afterward, Zimmer used words like poor, lethargic and disappointing to describe his team’s performance. He seethed over missed tackles, busted coverages and early three-and-outs. And he had “no idea” why some of his Vikings players looked disinterested in what was a must-win game inside their own stadium.

“I want to find out who is going to fight, because that was not a fighting performance there,” Zimmer said. “They were more physical than us today, played with more tenacity than we did. That’s usually how it goes.”

At no point during a terse news conference did he point a finger at himself.

The dud dropped his Vikings to 7-7. Up next are the Packers in Green Bay.

“It’s almost unbelievable,” left guard Alex Boone said of the Vikings squandering their 5-0 start to the season. “We have to take a good, hard look in the mirror. It’s not on, by any means, anybody but us. It’s frustrating, I think, to the point you want to break everything in sight. There’s so much talent on this team.”

 

Matt Vensel covers the Vikings for the Star Tribune. matt.vensel@startribune.com