Walton injured his shoulder and isn't expected to return to Thursday's preseason game against the Colts, Katherine Terrell of ESPN.com reports.
Walton totaled 17 yards and his first career touchdown over 10 carries before exiting the game. Given the competition he's in with Brian Hill and Tra Carson for the No. 3 role behind Joe Mixon and Giovani Bernard, any extended absence could bury Walton on the depth chart.