AJ McCarron finally gets signed by the Bills. But does he have what it takes to be a starter?

AJ McCarron earned his spot as an unrestricted free agent through an NFL arbitration hearing, freeing him up to chase a long term contract and a chance to shine as a starter away from the Bengals organization that drafted him. On Wednesday, he jumped at that opportunity, signing with the Buffalo Bills.

According to Pro Football Talk, it’s a two-year, $10 million deal with $6.5 million in play time bonuses. It’ll provide a fresh start for one of the league’s more intriguing backup quarterbacks and it’ll give the Bills a cheap stab at finding a starter.

McCarron has been effective in relief of Andy Dalton in his first four seasons in the league, completing nearly 65 percent of his passes and holding a respectable 93.7 passer rating in limited action throughout his career. He’s also been overwhelmed at times — including during a 2016 playoff start against the Steelers where he needed 41 passes to throw for just 212 yards.

Despite the buzz around McCarron when he won his grievance against the Bengals and was declared an unrestricted free agent, he was one of the last quarterbacks to sign in free agency. McCarron stayed unattached throughout the legal tampering period while Kirk Cousins, Sam Bradford, Case Keenum, Teddy Bridgewater, and Josh McCown all landed contracts.

He’ll join a quarterback depth chart that only features Nathan Peterman as competition.

Why did the Bills sign AJ McCarron?

McCarron is fortunate to be a still-intriguing prospect in a league that values quarterback play more highly than any other position. It was only a year ago the Bears handed Mike Glennon $18.5 million in guarantees after spending his prior two seasons throwing 11 combined passes. Chicago’s eagerness to pass out cash helped set the market for backup passers who look like potential league-average starters — a category into which McCarron fits neatly.

The former Bengal backup’s work in 2015 creates the hope he can continue developing and bring value as an efficient, game-managing quarterback who doesn’t generate back-breaking turnovers. He won’t turn 28 until the upcoming season, and there’s also hope that escaping Cincinnati, a black hole of hope every postseason from 2011-2015 and the past two regular seasons, will unlock his next level of NFL potential.

What are the concerns with McCarron?

While he’s 2-2 as a starter, those two wins came over teams that went 10-22 in 2015. He shrank against the league’s top defenses, as the Broncos and Steelers held him to an inefficient 5.4 yards per pass in his other two starts — a number that would have ranked dead last among qualified starters in 2017.

At the end of the day, McCarron’s experience as a starter is a small sample size. He looked good against bad defenses, and he looked rough against the good ones. It’s possible that McCarron has a future as a starter, but it’s far from a sure thing.