Report: Bills' McCarron suffers hairline fracture in collarbone

Buffalo Bills quarterback AJ McCarron reportedly suffered a hairline fracture of the collarbone in the first quarter of the team's preseason victory over the Cleveland Browns, according to The Buffalo News' Vic Carucci.

McCarron exited the contest in the first quarter, and the Bills later ruled him out for the game.

Following the win, head coach Sean McDermott said the quarterback will undergo further tests on his throwing shoulder, but couldn't provide further details, according to NFL Network's Tom Pelissero.

The severity of the injury is not yet known, but it could open the door for rookie Josh Allen to claim Buffalo's Week 1 starting quarterback job. He'll battle Nathan Peterman for the spot in the event McCarron misses an extended period of time.

McCarron spent the first four seasons of his career with the Cincinnati Bengals after being selected in the fifth round in 2014. He served as Andy Dalton's primary backup.

The Bills signed the former Alabama pivot to a two-year contract worth $10 million in March.