The Jacksonville Jaguars listed guard Will Rackley as questionable for Sunday's game against the Buffalo Bills.
Rackley reported concussion symptoms to the team on Saturday.
Rackley was initially injured Oct. 27 against the San Francisco 49ers. He missed the next two games.
Mike Brewster will likely start in place of Rackley if he cannot play. Rackley has started 11 games this season.
Also, the team activated tight end Allen Reisner from the injured reserve/designated-to-return list and linebacker LaRoy Reynolds, who was suspended four games for violating the NFL's performance enhancing drugs policy.
Reisner missed the last eight games with a knee injury.