Jackson (knee) didn't participate in Thursday's practice.
After serving as the Colts' lead back in last week's loss to the Patriots while Jonathan Taylor (ankle) missed his third game of the season, Jackson now appears to be the worst health among the two backs. Taylor returned to practice Wednesday as a limited participant before upgrading to full activity Thursday, while Jackson didn't log any reps for the second day in a row. Jackson could still put himself in position to play Sunday in Las Vegas if he manages some practice activity Friday, but with Taylor poised to rejoin the lineup this weekend, Jackson would likely be in store only for a change-of-pace role.