Bills quarterback Josh Allen's injured elbow dampens the anticipation around one side of Sunday's Vikings game in Buffalo. But the Bills' top-ranked scoring defense remains a difficult test yet for Kevin O'Connell's offense, although the Vikings appear to be catching a couple breaks there, too.

A few starting Bills defenders are hobbled this week. Their leading tackler, linebacker Tremaine Edmunds, has not practiced. Defensive end Gregory Rousseau is considered week to week because of a sprained ankle, Bills coach Sean McDermott told Buffalo reporters.

Rousseau has formed a potent tandem with Von Miller, the 33-year-old former All-Pro selection who signed with Buffalo in the offseason, and trails only Miller in quarterback pressures for the Bills, according to Pro Football Focus. His replacement, Carlos Basham, isn't a slouch; the 2021 second-round pick was already supporting a strong rotation.

Miller and Basham, along with defensive tackles Ed Oliver and DaQuan Jones, are a stiff test for a Vikings offensive line that struggled to protect quarterback Kirk Cousins in Washington.

"It's another challenge this week," O'Connell said. "But we just got to continue to work those things: stunts, games, all the different ways people try to stretch your protections. Whether it's true pressures, activating linebackers or secondary players or just trying to stress the individual offensive line. Our guys are up for the challenge. We work it every week."

The Vikings' protection issues came largely from overmatched guards Ezra Cleveland and Ed Ingram against the Commanders' duo of Daron Payne and Jonathan Allen. Buffalo can similarly stress offensive lines as Washington did during this third-down sack illustrated below.

The Bills like to rely on a four-man rush and play seven defenders in coverage, which puts the onus on Cousins to find the open target between a lot of Bills jerseys.

In coverage, the Bills prefer two-deep safety zones — or Cover 2 — to keep a lid on opposing passing attacks. They often succeed with a potent combination of rush and coverage, allowing only 6 yards per throw, ranking sixth fewest in the league.

This forces passers to dink and dunk as Cousins did on this 9-yard throw to receiver Justin Jefferson in the video below.

The Vikings need to do this more consistently in Buffalo.

"I've been the first one after games to say, 'Hey, we won. We can play better,'" Cousins said. "We'll always be saying that, but it's great to be having these conversations at 7-1 rather than at 1-7. But there's no doubt … this is a great test."

While Cousins likely won't face many extra rushers, the Bills have ways to create favorable matchups for pass rushers.

Buffalo has sure-tackling linebackers in Edmunds and Matt Milano, who also set up their teammates for success, even if they're not often blitzing. The Bills have the seventh-lowest blitz rate (16.6%) in the league, according to Pro Football Reference, similar to the Vikings at 15.1%.

Buffalo held down the Chiefs in a 24-20 win at Arrowhead Stadium on Oct. 16 by consistently pressuring quarterback Patrick Mahomes with four rushers.

The Bills let Mahomes into the red zone only twice, intercepting him on the opening possession. Vikings center Garrett Bradbury and guards Ingram and Cleveland will have to hold up in one-on-one spots against Oliver (91), who helped wreck a third-and-goal play in Kansas City thanks to a presnap alignment that gave him a solo matchup on right guard Trey Smith.

"They play fast, they get up the field," Bradbury said. "Really physical group and they've won a lot of games because they have a really good defense. It's going to be a good challenge for us."

In the play below, the Bills go with a five-wide front. Milano (58) hovers over the left guard even though he has no intention of rushing. This sets up a five-on-five look for the offensive line. Oliver works back Smith, the right guard, and forces Mahomes to flee. Mahomes eventually takes a chance and throws a pick.

There are still holes to find in the Bills' two-deep safety coverages, should Vikings blockers hold up. Communication amid a road crowd at Highmark Stadium will also be important. Like any defense that relies on a four-man rush, the Bills often deploy twists, or "stunts," with defensive linemen setting each other up by interfering with blocks. Cleveland and Ingram didn't seem to handle them well in Washington.

Even if they can't take down Cousins, Bills rushers will get their hands up to try to deflect passes and create takeaways. Buffalo is one of four defenses with more interceptions (11) than passing touchdowns allowed (8) this season. Their defensive linemen have deflected nine passes in eight games.

"They're very opportunistic," Vikings offensive coordinator Wes Phillips said.

Keeping Cousins clean will be key. Protection helped the Chiefs get going against Buffalo during a go-ahead fourth-quarter drive in which Mahomes found tight end Travis Kelce for a 19-yard completion. Kansas City's right tackle and right guard successfully picked up a Bills' defensive line twist, giving Mahomes time to lob a pass to Kelce in the sideline hole of Buffalo's two-deep zone coverage.