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Amari Cooper's 32-yard catch and run in the second quarter of the Vikings' loss to the Cowboys on Sunday was the 36th pass of at least 20 yards surrendered by this Vikings defense through 10 games.

The Vikings' top-ranked 2017 defense allowed just 35 such plays all season. The issue during Cooper's big play, which set up a Cowboys field goal before halftime of a three-point loss, is all too familiar during a transitional season bottoming out again for a young and injury-ravaged defense.

Coach Mike Zimmer saw problems wider than coverage busts.

"We had a couple mistakes," Zimmer said. "Honestly, I think a little bit had to do with these guys feeling their oats a little bit. Now they're going to be play makers and go out and do this and do that instead of just doing their job and I think that showed up a few times as well."

There's no cure-all to the ebbs and flows of inexperience after the Vikings defense followed up three straight NFC North wins by letting a previously dormant Cowboys offense reignite at U.S. Bank Stadium. The pass rush was minimal. The secondary, which we'll discuss below, crossed wires or was simply beat in key moments.

"From the secondary down to the defensive line and the linebackers," safety Anthony Harris said, "we all kind of took turns making mistakes and maybe not being where we needed to be."

1. A couple cornerbacks are likely in Mike Zimmer's doghouse after this loss, including Kris Boyd. The second-year defender has still shown more promise than many of his fellow corners, but Sunday was a rough outing that included an apparent mental block on this first-and-10 play with 15 seconds before halftime.

It's a single-high safety defensive coverage, and an apparent form of Cover-3 with cornerback Chris Jones (#26) covering the vertical route on the opposite side of Boyd (#29). You could assume the other outside corner, Boyd, should do the same against an identical Cowboys route pattern. He does not.

Safety Harrison Smith (#22) lurches forward to cover the flat, just as the Vikings' other inside defender, Jeff Gladney, does on the opposite side of the field. There is nobody left to cover Cooper (#19) with Boyd and Smith in the same area.

2. How did Cowboys tight end Dalton Schultz get that open for the game-winning touchdown? Trying to do too much was a problem when Harrison Smith appears to come off his assignment when anticipating a pass to receiver CeeDee Lamb.

Cornerback Jeff Gladney (#20) follows Lamb (#88) across the formation before the snap. The Vikings are in man-to-man coverage, according to Zimmer. So, Lamb is Gladney's guy, at least at this point. Smith (#22) can be seen waving to Gladney to come back to that side as Lamb begins to motion.

Gladney does, but not before Smith appears to try to jump a quick pass to Lamb. This leaves Cowboys tight end Dalton Schultz (#86), presumably Smith's guy, wide open for the touchdown.

"We're in man to man," Zimmer said, "and the guy [Lamb, #88] went in rocket motion and the guy [Smith?] came off of his guy trying to help another guy [Gladney?]."

3. Zimmer also tipped his cap to Cowboys' fourth-down play on that final scoring drive. With the Vikings often playing two-deep safety coverages in passing situations, like this 4th-and-6 play, the Cowboys isolate Minnesota's safety help by putting all three receivers on the wide side of the field.

The vertical route down the seam forces safety Anthony Harris to keep his depth, while Gladney (#20) is left alone on Cooper (#19) and loses in a tough spot.

The ball may even be a tad late from Cowboys quarterback Andy Dalton, but Cooper gets enough separation from Gladney.

4. Rookie cornerback Cameron Dantzler didn't start against the Cowboys, but Chris Jones' time over him should be short. Zimmer "had a problem" with Jones not tackling Cowboys running back Tony Pollard during a 42-yard touchdown run in the fourth quarter, and it'd be surprising if Jones remained as involved in the rotation (unless confidence in Boyd has slipped that much).

Dantzler wasn't targeted very often against the Cowboys, but he was the kind of aggressive run defender that Jones, well, was not. But he was eased back into the mix, coming off the bench after a two-game absence in the concussion protocol after that scary collision Nov. 1 left him taken to a hospital in Green Bay.

The good news, for the Vikings, is Dantzler appeared unfazed in his return. On this second-and-10 play in the first quarter, Dantzler makes the right read when a Cowboys receiver motions inside before the snap.

While Dantzler doesn't make the tackle, he gets enough of Pollard to keep him pinned inside where he runs into linebacker Eric Wilson (#50) for a four-yard gain. Offenses are bound to keep running outside on the Vikings defense if their corners play like Jones, but not so much if they play like Dantzler.

5. Even with the miscues, the Vikings defense had a couple chances to help seal the game on the game-losing drive. Just as cornerback Holton Hill dropped a potential game-winning interception during the Week 3 loss to Tennessee.

Boyd's day ended with a dropped interception at the goal line just before Dalton threw the touchdown to Schultz. A few plays earlier, linebacker Eric Kendricks nearly upped the difficulty level with what could've been his second interception on this fingertip deflection.

On first-and-10, this is all reaction speed from Kendricks as he moves with the play-action fake, shifts to his right, his left and back to his right while reading Dalton's eyes as he tries to find Michael Gallup. The flow of the Cowboys' run fake takes Kendricks and the defense to his left, but he takes away a backside throwing lane with impeccable awareness and athleticism.

"Those are tough plays," Harris said. "Kendricks does a great job of trying to come back out of his zone and get a hand on the ball and come away with the interception. Boyd as well in the end zone, trying to compete for position."