The Buffalo Bills enter 2021 NFL free agency coming off a 13-3 season in 2020 and have 15 unrestricted free agents.

Fresh off an appearance in the AFC Championship Game, the Bills' future has not looked this bright since quarterback Jim Kelly powered their offense in the early 1990s. With MVP runner-up Josh Allen and All-Pro Stefon Diggs forming one of the most potent quarterback-wide receiver duos in the league, the Bills appear ready to compete with any team in the NFL and challenge the two-time reigning AFC champion Kansas City Chiefs.

Here's what to expect from the Bills when the NFL offseason hits high gear with the start of free agency on March 17:

QUARTERBACK

Under contract: Josh Allen, Jake Fromm, Davis Webb

UFA: Matt Barkley

Game plan: With Barkley's impending free agency, the Bills would be wise to add a veteran backup to create competition for Fromm, a 2020 fifth-round pick. Webb is an integral presence in the locker room and will likely return as the team's practice squad quarterback.

RUNNING BACK

Under contract: Devin Singletary, Zack Moss, Christian Wade, Antonio Williams

UFA: Taiwan Jones, T.J. Yeldon

Game plan: The Bills have publicly expressed a desire to improve their run game -- whether they do that via the draft or free agency remains to be seen. Coach Sean McDermott prefers to spread the ball out in the backfield, but the type of back Buffalo adds in free agency depends on whether they believe Moss or Singletary can operate as a lead back.

WIDE RECEIVER

Under contract: Stefon Diggs, Cole Beasley, Gabriel Davis, John Brown, Isaiah Hodgins

UFA: Andre Roberts, Isaiah McKenzie

Game plan: Wide receiver is arguably the Bills' strongest position and one that's not high on the priority list in free agency. Roberts has made the Pro Bowl as a returner in each of his two seasons in Buffalo and is the more likely candidate to return of the team's two free agents.

TIGHT END

Under contract: Dawson Knox, Lee Smith

UFA: Tyler Kroft

Game plan: There will be a new addition to the Bills' tight ends room next season -- especially after general manager Brandon Beane made it clear the team didn't get enough from the position during the 2020 season. They need an alpha who can be a true threat in the passing game, but don't have the cap space to pay top dollar for it. A player such as Jonnu Smith would fit right into their wheelhouse.

OFFENSIVE LINE

Under contract: Dion Dawkins, Cody Ford, Mitch Morse, Ryan Bates, Trey Adams, Jordan Devey

UFA: Jon Feliciano, Daryl Williams, Ty Nsekhe, Brian Winters

Game plan: Buffalo's focus will be on bringing several of their unrestricted free agents back for next season -- primarily Feliciano. The Bills also like restricted free agent Ike Boettger, who started seven games in 2020. Either way, with three starters returning, Beane has work to do this offseason on the offensive line.

DEFENSIVE LINE

Under contract: Jerry Hughes, Mario Addison, Ed Oliver, Vernon Butler, Star Lotulelei, Quinton Jefferson, AJ Epenesa

UFA: Trent Murphy

Game plan: The Bills' defensive line is littered with contracts currently hamstringing the team's financial flexibility -- all while still needing improvement. Hughes was the team's most effective pass-rusher last season, but they need a lineman who can consistently pressure the quarterback.

LINEBACKER

Under contract: Tremaine Edmunds, Tyler Matakevich, A.J. Klein, Tyrel Dodson

UFA: Matt Milano, Del'Shawn Phillips

Game plan: Buffalo's top priority is bringing back Milano, but he might be too expensive for the Bills to sign. If he leaves, they'll need another linebacker with coverage skills like Milano brought to their defense.

CORNERBACK

Under contract: Tre'Davious White, Taron Johnson, Dane Jackson, Siran Neal

UFA: Josh Norman

Game plan: Three-year starter Levi Wallace is a restricted free agent this offseason, and the Bills should make an effort to bring him back. The team also likes Jackson, a 2020 seventh-round pick. The Bills are more likely to draft a cornerback than sign one.

SAFETY

Under contract: Micah Hyde, Jordan Poyer, Jaquan Johnson

UFA: Dean Marlowe

Game plan: Hyde and Poyer are one of the league's best safety tandems, and the Bills like what Johnson brings on special teams and on defense in a pinch. Marlowe is also too valuable to let walk -- especially if Buffalo can't bring Milano back. In short, the Bills' focus is internal when it comes to the safety position, rather than bringing in a free agent.

SPECIALIST

Under contract: Tyler Bass, Reid Ferguson

UFA: None

Game plan: Corey Bojorquez was one of the league's best punters last season and is a restricted free agent this offseason; he will be back in Buffalo in 2021.