The Buffalo Bills will be without the services of quarterback A.J. McCarron for several weeks with a hairline fracture in his collarbone, reports the NFL Network's Ian Rapoport.

Rapoport was confirming a report on late Friday night from the Buffalo News' Vic Carucci and notes that there is no timeline for the 27-year-old Alabama product's return.

Signed to a three-year deal in the offseason from the Cincinnati Bengals, McCarron incurred the injury during the Bills' Friday night preseason 19-17 victory over the Cleveland Browns. McCarron started the game and played its first four series, all of which were three-and-outs. He finished the game with 12 yards on 3-for-6 passing.

A backup for the first four years of his pro career behind Andy Dalton, McCarron had a real chance to start for the Bills this season ahead of first-round pick Josh Allen and second-year pro Nathan Peterman, but that has been thrown into doubt with the injury.