Marshall will miss his second consecutive game because of a back injury. Thomas suffered his second concussion of the season in last Sunday's win at Cincinnati.
Linebacker Kevin Burnett was limited in practice Friday and listed as questionable because of an ankle injury.
Running back Reggie Bush (knee), receiver Brian Hartline (quadriceps), cornerback Nolan Carroll (Achilles) and safety Reshad Jones (back and heel) were listed as probable. All participated fully in practice.
Carroll is expected to start for Marshall. Thomas' absence likely means more carries for rookie Lamar Miller.