Jackson (illness) isn't practicing Thursday, Jonas Shaffer of The Baltimore Sun reports.
Jackson's unspecified ailment has kept him away from the team for the first two days of Week 18 prep, but he'll still have a good chance to play Sunday against the Bengals if he's able to practice Friday in some capacity. Since making his season debut Week 9, Jackson has compiled a 9-153-0 receiving line on 17 targets through his first seven games with Baltimore.