The seventh overall pick in the 2018 NFL Draft was taken to the locker room after hitting his head hard on the turf during the second quarter of Sunday's game.
During the third quarter, the Bills announced Allen had been cleared to return to the game after being evaluated for a head injury.
Up until the time he was hurt, Allen had completed 6 of 12 pass attempts for 34 yards with no touchdowns or interceptions. He had been sacked five times for a loss of 39 yards.
Nathan Peterman took over in the third quarter with the Bills trailing, 23-0. Peterman completed 6 of 6 attempts, including a 17-yard strike for a touchdown to make the score 23-7.