CLEVELAND — Buffalo quarterback AJ McCarron sustained a potentially serious shoulder injury, throwing the Bills’ quarterback situation into total disarray, during a 19-17 win over the Cleveland Browns on Friday night.

McCarron, who signed with Buffalo as a free agent for a chance to start after four years as a backup in Cincinnati, completed just 3 of 6 for 12 yards during four series.

The 27-year-old didn’t show any obvious signs of being hurt — he was hit hard from behind by Myles Garrett and sacked by Larry Ogunjobi — and the Bills didn’t disclose his injury until the fourth quarter.

McCarron is competing with Nathan Peterman and rookie Josh Allen for Buffalo’s starting job.

Allen, the No. 7 overall pick, out-performed McCarron and Peterman rallied the Bills (2-0) with a late touchdown pass to tight end Nick O’Leary.

Rookie Nick Chubb and Carlos Hyde had touchdown runs for the Browns (1-1).

The Bills have wanted to take a slow approach with Allen, letting him watch and learn behind McCarron and Peterman. However, those plans may have to be scrapped.

Peterman who started two games as a rookie in 2017, was 8 of 10 for 113 yards and a score.

Allen fired a 2-yard TD pass to Rod Streater in the second quarter and led the Bills on three scoring drives. He completed 9 of 13 passes for 60 yards and was sacked once.

Panthers 27, Dolphins 20

CHARLOTTE, N.C. — Christian McCaffrey had 120 yards from scrimmage in the first half, including a 71-yard touchdown run and the Carolina Panthers defeated the Miami Dolphins 27-20 Friday night in a preseason game.

McCaffrey had 92 yards rushing on five carries and caught four passes for 28 yards for Carolina (2-0).

Ryan Tannehill was an effective 14 of 17 for 100 yards despite playing without wide receivers DeVante Parker and Kenny Stills.

Chiefs 28, Falcons 14

ATLANTA — After a dismal showing in the first preseason game, Matt Ryan and the Atlanta Falcons found their offensive rhythm Friday.

Ryan guided the Falcons right down the field for a touchdown on their first possession, hooking up with Austin Hooper on a 4-yard scoring pass , and led another impressive drive before calling it a night in a 28-14 loss to the Kansas City Chiefs.

Ryan finished 5 of 7 for 90 yards, looking very much like the quarterback who won the MVP during the 2016 season even though two of his top weapons, receiver Julio Jones and running back Devonta Freeman, were held out for the second week in a row.

Giants 30, Lions 17

DETROIT — Davis Webb took advantage of his opportunity to play for Eli Manning, throwing a go-ahead touchdown in the second quarter to help the New York Giants beat the Detroit Lions 30-17 Friday night.

Webb was 14 of 20 for 140 yards with an 8-yard TD pass to Wayne Gallman Jr., who scored for a second time later in the game. Webb showed poise in the pocket.