The Buffalo Bills exceeded all expectations when they reached the AFC Championship Game and just fell short against the vaunted Kansas City Chiefs. The Bills won 13 games in the regular season and only lost three contests.

Bills quarterback Josh Allen transformed from a promising, young quarterback into an MVP candidate, with All-Pro Stefon Diggs leading the deadly receiving crops and Cole Beasley having a tremendous season. The defense was an above-average unit with solid pieces and a Pro-Bowler in cornerback Tre'Davious White.

This upcoming season will be pivotal to the franchise since it is the last year of Allen's rookie contract. He has a cap number of $6,910,056, which is a bargain even if he regresses slightly.

Buffalo is currently looking at nearly $20 million in cap space, which gives them wiggle room to re-sign free agents and go on the market to look for other options. 

However, here are two free agents the Bills should stay away from.

Patrick Peterson, CB

The Bills have a star corner in White, but cornerbacks Levi Wallace and Josh Norman are hitting free agency. Peterson might be a tempting option for the front office given his track record. Taking a defensive back with the fifth overall pick is risky, but Peterson lived up to expectations in Arizona, as he made All-Pro three times early in his career.

From his rookie year in 2011 to 2018, he was selected to the Pro Bowl each season and was regularly tasked with taking on the opposing team's best receiver. Peterson's physical gifts were so impressive that he was even used on punt returns and scored four touchdowns in his first season.

Things took a turn for the worse when Peterson was suspended for six games in the 2019 season due to violating the league's policy on performance-enhancing drugs (PED). Although he only played in 10 games, his production was similar to his Pro Bowl years, however, there is a rule that players with PED suspensions are ineligible for the Pro Bowl.

Last season, Peterson looked like a different player … and not in a good way. He regularly got cooked by good receivers and racked up 10 penalties, which tied for second-highest in the league. For reference, the team with the fewest penalties, the New England Patriots, had 62 as a team.

Peterson is still a serviceable defensive back, but his form has significantly declined, so the Bills should tread lightly. On another note, with his size and veteran savvy, he might consider playing safety.

Alejandro Villanueva, OT

Recent trends show the Bills rarely draft offensive linemen, so it is safe to assume they will address the holes in the unit through free agency. Buffalo has five offensive linemen hitting free agency. One of them is tackle Daryl Williams, who outplayed his bargain contract. In a pass-heavy offense, protecting Allen is made even more important. 

Even among NFL tackles, Villanueva is huge, standing at 6-foot-9 and 320 pounds. Since 2015, he has played 16 games each season for the Pittsburgh Steelers. Villanueva is a good pass protector and was the best run blocker on the Steelers' line, though the latter is not saying much.

Although he is 32 years old, Villanueva has quality football left in him and tackle can be filled by older players; just look at Andrew Whitworth. Also, Villanueva does not have nearly as much mileage as other players his age. He projects as an upgrade for most lines and is one of the better tackles in free agency.

One issue with the Bills signing a player like Villanueva is he is not not as mobile as other tackles. One of the reasons why the Williams signing went well was because he had experience playing with a rushing quarterback in Cam Newton during his stint with the Carolina Panthers. On the other hand, Villanueva has played with Ben Roethlisberger, a pocket passer.    

While Buffalo usually wins through Allen's arm, it would be good to get some semblance of a run game going to make the offense less predictable. The Bills heavily rely on disguising passing plays as runs and opposing teams frequently took the bait, even though they did not have much of a ground attack. Villanueva would probably not be a negative in the run game, but he also likely wouldn't be a positive. 

The biggest concern, though, is the money it would take to sign Villanueva. While Buffalo has the cap space, the club also needs to fill out its offensive line and other holes for a Super Bowl run. Villanueva might command a salary of $14,000,000 per season and a multi-year contract. At that price, they could just re-sign Williams and get one or two guards.