Five Vikings developments to keep an eye on against the Bills

As the Vikings prepare to open the preseason on Thursday night in Buffalo, here are five things to watch in their game against the Bills:

Mackensie Alexander's debut in the nickel

The Vikings are trying to replace Captain Munnerlyn, who followed a rocky first season in their defense with two solid years as their nickel corner before signing with the Panthers. They'll give the first crack at the job to Alexander, the second-year corner who could be counted on to play a significant role in the defense.

Alexander played only 68 snaps as a rookie, but in 2017 he'll be asked to play what's effectively become a starting position in the NFL. According to ESPN Stats and Information, opponents had at least three wide receivers on the field 69.8 percent of the time against the Vikings last year.

The wide receiver battle

Michael Floyd will look to build on a strong training camp, where he made a number of contested catches and used his footwork to separate from defensive backs on intermediate routes. He's trying to make an impression before his four-game suspension starts at the beginning of the regular season.

Laquon Treadwell hasn't practiced since an in-practice fight with Antone Exum last week, and Jarius Wright is trying to reassert himself after catching just 11 passes last year. Rookies Rodney Adams and Stacy Coley should get plenty of work with the second-team offense after Sam Bradford and company come out of the game.

The Vikings' approach in training camp suggests they're interested in making Joe Berger their right guard, while starting either Nick Easton or rookie Pat Elflein at center. Easton was listed first on the Vikings' initial depth chart and figures to start on Thursday. Coach Mike Zimmer indicated he could mix and match personnel in the preseason, though, rather than taking the entire first-string offense out of the game after a series or two. The Vikings might use the opportunity to give Easton a longer look in preseason games.

Weak-side linebacker battle

As the Vikings look for their replacement for the retired Chad Greenway, fourth-round pick Ben Gedeon has put himself in the mix with a strong training camp.

"He makes a lot of plays for us," defensive coordinator George Edwards said. "He does a good job in the run game of getting on and off blocks. He's got a good understanding of the passing game as far as the matchups underneath. We are trying to get our best three guys out there and we're just having a competition, and we'll just see as it progresses through the preseason, through camp, but he's earned a spot to get up there and compete."

Gedeon would need a strong preseason to beat out Edmond Robinson or Emmanuel Lamur for the job, but he's made some impressive plays in coverage in addition to faring well against the run, ranging back to deflect a pass over his head on Monday. He's worked at both middle and outside linebacker and is listed on the Vikings depth chart in the middle right now, while Robinson and Lamur share the top spot on the weak side.

The Vikings have more open spots on special teams than they have had in years, with Marshall Koehn trying to unseat Kai Forbath as the kicker and Ryan Quigley battling Taylor Symmank for the punting job. They'll also take a look at Adams and Coley as kick returners, and they might give Isaac Fruechte a chance to push for the job after the receiver put in some strong work as a return man in training camp.