Viking test: Can Justin Fields outfox Mike Zimmer’s blitzes?

Bears offensive coordinator Bill Lazor was a 31-year-old offensive quality-control coach for the Falcons in 2003 when, in his first NFL game, he watched the Cowboys run a complicated blitz package against his new team.

The Cowboys’ defensive coordinator 18 years ago: Mike Zimmer, who is now the coach of the Vikings, the Bears’ opponent Monday night.

“We know coach Zimmer has always had an extensive third-down blitz package,” Lazor said this week. “He was blitzing back then. So obviously things have adjusted and changed since then, but he’s always had a very extensive, very sound, very challenging third-down package. And they still do.”

That’s bad news for a rookie quarterback.

Justin Fields will make his 10th career start against Minnesota. He has never faced someone like Zimmer, who is fanatical about crafting exotic blitz packages.

Fields is no stranger to being put on his back. He has been sacked 12.5% of the time this season, by far the most of any quarterback in the league. And he faces the possibility of playing behind backup blockers — left tackle Jason Peters won’t play because of a high ankle sprain, and rookie right tackle Larry Borom was put on the reserve/COVID-19 list.

Absent any impressive stats, Fields has cited his ability to read defenses —“I feel like I’ve been seeing the field well,” he said — as evidence that he’s getting better. Zimmer will provide perhaps his toughest test.

“They disguise coverages really well,” Fields said. “They bring a lot of blitz packages on third downs. We just have to stay out of long third downs and execute on third down.”

Few do. The Vikings allow their opponents to convert 35.3% of their third downs, the fifth-stingiest clip in the league.

“I have a lot of respect for what they do on third down,” coach Matt Nagy said Saturday. “For Justin, it’s gonna be a really good opportunity for him to be able to see some of the things they do.”

It’s not how often the Vikings blitz — 25.6% of the time, 13th-most in the league — but, rather, how they look doing it.

“I think, probably, the best thing they do is they disguise,” Nagy said. “So it’s a cat-and-mouse game where they like to show you one way and come from another — and then show you one way and come from that way.

“So we’ve got to be really locked in and be good with what we’re doing schematically, whether it’s via protections or whether it’s through the air — or whether it’s through the run.”

The Bears are lucky Fields’ first exposure to Zimmer came in his 10th start, not his first. Still, the Bears holding walkthroughs all week — in lieu of practices — puts Fields at a disadvantage.

Zimmer, who calls the Vikings’ defensive plays, is best known for his “Double Mug” look, in which an inside linebacker stands in each “A” gap — one over the center’s left shoulder, another over his right.

The Vikings average a league-high 3.2 sacks per game.

Forty-seven NFL players have five sacks or more — and the Vikings employ four of them. Even safety Harrison Smith has three.

“The biggest thing, obviously, for us up front, to [Fields], is just having the communication of where we’re going,” center Cody Whitehair said. “That’s what we’re working on this week, just basically over-communicating clarity so that he knows what we’re doing.”

There’s a difference, of course, in the Vikings blitzing Fields vs. attacking last week’s opponent, the lumbering Ben Roethlisberger. While the 39-year-old Steelers quarterback has seen it all before, Fields has the speed to run away.

That’s a major concern for Zimmer.

“You get bottled up, and next thing you know, he’s out and out in space,” Zimmer told reporters this week. “And you got guys spread out all over the place, and you have to make a tough tackle on an open-field runner who is a really good athlete.

“That always makes it more difficult, when the quarterback can run.”

The Bears have praised Fields’ composure all season. That will be tested Monday night — and again in the season finale, when the Bears face the blitz-happy Vikings again.

“We all know what Justin can do,” Whitehair said. “He’s very talented. But I just love the poise that he brings.

‘‘He’s the same guy every day. And that’s all you can ask for with the quarterback — just to be the same guy and keep the same poise no matter what happens. And he’s done that.”