Josh Allen and the Buffalo Bills host the Pittsburgh Steelers on Sunday to open the regular season. Buffalo and their deep, talented roster are Super Bowl contenders, while 39-year old Ben Roethlisberger is looking to prove that he still has one or two quality seasons left in the tank.

Here are the four biggest storylines to watch in NFL Week 1.

Can the Bills defend tight ends?

In 2020, Buffalo was one of the worst teams in the NFL when it came to defending opposing tight ends. They allowed the most receptions (92), second-most yards (993) and 12th-most touchdowns (eight) to the position. While those struggles can partly be attributed to Matt Milano and Tremaine Edmunds dealing with injuries at varying points during the season, it’s still a concern entering 2021.

While the Steelers’ wide receiver corps, along with rookie running back Najee Harris are the headliners on offense, you can bet that offensive coordinator Matt Canada will look to get tight ends Eric Ebron and rookie Pat Freiermuth involved heavily on Sunday.

Bills LB Tremaine Edmunds poised to bounce back after down 2020 season

Ebron quietly caught 56 passes for 558 yards and five touchdowns last season and was targeted heavily in the redzone. The addition of Friermuth, an athletic 6-foot-5, 251-pound specimen that can run, catch and block only creates more mismatches for the Steelers’ offense.

Milano is one of the top coverage linebackers in the NFL and was paid as such during the offseason. Edmunds is fully healthy and entering a contract season, so there won’t be room for many excuses if the 22-year old struggles against Pittsburgh’s pair of seam stretchers.

Bills’ new-look DL VS. Steelers’ young OL

The Buffalo Bills were “intentional” about upgrading their pass rush during the offseason and after three preseason games, it’s evident that the team is in a much better space than a year ago. Second-year defensive end A.J. Epenesa has been explosive off the edge given his new-look body type, while rookie first-round draft pick Greg Rousseau looked polished and dominant at times.

Defensive tackle Star Lotulelei’s return helps Ed Oliver, who’s garnered quite a bit of praise in his third training camp as well, while Jerry Hughes, Efe Obada, Boogie Basham and Mario Addison will provide pass rush in waves from the edge.

A.J. Epenesa discusses newfound ‘get-off,’ versatility of Bills’ pass rush

Sunday will be their first true test, though, against a young, inexperienced Steelers offensive line that has a lot of question marks from left to right.

After losing Alejandro Villanueva and David Decastro, Pittsburgh is rolling out two rookie Day 2 picks at key positions – Dan Moore Jr. (fourth round) at left tackle and Kendrick Green (third round) at center. Green will be flanked by left guard Kevin Dotson, a second-year player with 358 snaps under his belt, and right guard Trai Turner, a veteran that was unsigned for much of the offseason. Chukwuma Okorafor will start at right tackle.

This is a prime opportunity for Buffalo’s pass rush to get their legs under them against an inferior offensive line, with winnable matchups across the board.

Ben Roethlisberger gets the ball out quickly, as his 13 sacks behind a questionable line a year ago shows. According to Pro Football Focus, Roethlisberger had the lowest time in the pocket of all quarterbacks in 2020, averaging just 2.17 seconds from dropback to pass. With an arsenal of talented receivers and tight ends at his disposal, getting pressure, hits and sacks on Roethlisberger to force him into errant throws will be critical for the Bills’ defense to secure a Week 1 victory.

Josh Allen & Co. vs. Weak Steelers secondary

Josh Allen’s first game as a $258 million man comes against one of the weakest cornerback groups in the NFL. Minkah Fitzpatrick is one of the league’s most dynamic playmakers at the safety position and is coming off of a 2020 season in which he tallied 79 tackles, four interceptions, 11 pass breakups and one forced fumble.

But top cornerback Joe Haden is 32-years old, while Cameron Sutton, Justin Layne, James Pierre and Ahkello Witherspoon will have their work cut out for them against Buffalo’s loaded receiver corps. Stefon Diggs is a nightmare for any defensive back, and it’s tough to see Joe Schobert or Devin Bush – who’s returning from a torn ACL – enjoying much success against Cole Beasley over the middle.

Gabe Davis looks like he’s primed to take a big step for the Buffalo Bills after a surprisingly impactful rookie season and Emmanuel Sanders, who will make his Bills debut, is still as shifty as ever.

Pittsburgh’s defensive line is stout but if T.J. Watt’s contract impasse doesn’t get resolved, Allen will have all the time in the world to pick apart a porous secondary.

How improved is Buffalo’s run defense?

The Buffalo Bills struggled to consistently defend the run in 2020, surrendering 123.2 yards-per-game on the ground, the 20th-best rate in the NFL. While Star Lotulelei’s absence had a lot to do with their struggles, it’s still an area of concern that will be monitored early this season.

The Bills starters played against the Packers’ second and third-string offense to close out the preseason and the results were shoddy at best. A.J. Dillon and Kylin Hill helped Green Bay amass 65 yards on 15 carries during the first half – hardly a promising effort by what’s expected to be a rejuvenated defensive unit.

While preseason results can, and should mostly be taken with a grain of salt, it would’ve been encouraging to see Buffalo’s starters shut down a group of backups, yet here we are.

In Week 1, the Bills will be tasked with slowing down Pittsburgh Steelers rookie Najee Harris, a first-round back that was an absolute phenom during his career with the Alabama Crimson Tide. Harris is the latest in a lineage of dominant Alabama backs and finished his career with 6,483 rushing yards and 46 touchdowns while averaging 6.0 yards-per-carry. Harris is lethal as a receiver out of the backfield, catching 80 career passes for 781 yards and 11 touchdowns.

Harris does it all. He’s big, standing 6-foot-1, 232-pounds, but has breakaway speed, elite vision and quickness and is impactful as a receiver, too. He may be a rookie, but Harris shouldn’t be overlooked, as he’ll present a challenge for any defender who’s tasked with taking him on in space.