Jackson was held out of practice Wednesday with a knee injury.
Meanwhile, Jonathan Taylor (ankle) returned to practice as a limited participant after missing a 26-3 loss to the Patriots on Sunday. Jackson was the lead back in that game but finished with only 36 yards on 13 touches in an ugly outing for the Indianapolis offense in what turned out to be Frank Reich's final game as head coach. It's possible Jackson gets another start Sunday in Las Vegas, but only if he makes progress later in the week while Taylor heads the other direction.