Allen got rocked by a couple of Patriots defenders and hit the turf hard.
Bills quarterback Josh Allen was knocked out of the team's 16-10 AFC East loss to the Patriots after taking a devastating hit in the fourth quarter Sunday.
The injury occurred on a seven-yard scramble from Allen with the Bills trailing 16–10. As Allen was being tackled by safety Duron Harmon, Jonathan Jones launched into Allen's head with his helmet. Jones was flagged for unnecessary roughness but remained in the game.
Allen stayed on the ground briefly before walking off the field under his own power. The second-year quarterback jogged into the locker room for further evaluation.
Bills quarterback Sean McDermott told reporters after the game that Allen was in the concussion protocol.
"It's disappointing because there's no room for that kind of play in the NFL," McDermott said.
Allen was replaced by Matt Barkley, who completed a 17-yard pass to John Brown on the ensuing play before failing to convert a fourth-and-goal later in the drive. Barkley went 9-of-16 with 127 yards, but he threw an interception as he tried to lead the Bills back late in the fourth quarter.
Allen was 13-of-28 for 153 yards and had three interceptions before leaving the game.
Buffalo next faces the Titans on Oct. 6, while New England will next take on the Redskins the same day.