Watch the video above and get a quick analysis of the game from Jon Scott.

CLEVELAND (AP) -- 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.

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.

 

 

Not only did he outshine McCarron, but he stole some of the spotlight from Baker Mayfield, the No. 1 overall pick making his home debut. Mayfield finished 7 of 13 for 75 yards.

Cleveland starting QB Tyrod Taylor didn't do much against his former team, completing 4 of 7 pass for 22 yards in four series. The Bills traded him in March to the Browns.

Allen, who was promoted to second-string earlier this week, replaced an ineffective McCarron with the Bills trailing 7-0 and led Buffalo on two scoring drives for a 10-7 halftime lead.

Allen badly misfired on his first pass attempt before settling in. Helped by a 22-yard run from Marcus Murphy, Allen took the Bills to the Cleveland 2. After two running plays were stuffed, Allen showed poise and precision with his TD pass.

Dropping back, he first avoided rushing Browns end Nate Orchard and then took several steps toward the line of scrimmage before threading his pass to Streater in the back of the end zone.

Stephen Hauschka kicked field goals of 33 and 53 yards for Buffalo.

After gaining just 50 yards rushing on 33 carries last week, the Browns put an emphasis on their running game in practice.

The extra work seemed to pay off as Cleveland ran for 63 yards on its opening possession, which ended with Hyde's 4-yard TD run.