Jackson, the team's leading tackler, has a hamstring injury that he sustained this week in practice. Dawson has been inactive for Cleveland's past two games with a left calf injury and has not been seen around the team's training facility.
Billy Cundiff will likely make his third straight start for Dawson against the Bills.
If Jackson can't play, rookie linebacker David Veikune is the most likely player to take his starting spot. Jackson has been getting treatment this week and said he doesn't want to rush back.
Jackson led the NFL with 188 tackles last season.