Overreliance on Aaron Rodgers
First of all, the team has to note that Breece Hall probably isn't 100% right away, hence the Dalvin Cook signing, who's also a back that can be dangerous in the receiving game. So the Jets would most likely prefer to pass the ball, so they would try to carve up the Bills defense in the passing game.
Obviously, we all know how good of a passer Rodgers is, but it’s important to note that Rodgers is with a whole new team and it may take a while to develop chemistry with some new players.
Rodgers is also turning 40 this season, so overly relying on a person at that age typically doesn’t turn out great, unless that person is Tom Brady of course.
Buffalo Bills have star defensive players returning with healthier bodies
Though the Buffalo Bills are going to be a little short on defense with Von Miller on the PUP list and with Tremaine Edmunds gone in Chicago, they still have defensive pieces like Matt Milano, Ed Oliver, Taron Johnson, both Micah Hyde and Jordan Poyer, along with a healthier Tre'davious White.
So the Bills' secondary would be expected to perform better than last season, where that part of the defense would have issues with Hyde out for most of the season, as well as White coming back mid-season while still not fully recovered from his ACL injury.
Now with healthy bodies coming into this season, those players are expected to perform and make a big impact for this Bills defense.