Hillis, who has been limited in practice all week, strained his hip in last Sunday's loss to Baltimore but sounded confident he'd play Thursday.
"The hip's OK, but everything should be fine for Thursday; I should be ready to play," Hillis said on Tuesday.
Hillis missed five games earlier this season with a hamstring injury.
McCoy has been a full participant in practices this week despite a knee injury also suffered in the loss to the Ravens. He came out for one play but finished the game.
"Colt's fine; I think he's fine," Browns coach Pat Shurmur told the team's website. "I think there were a lot of guys that were game-sore and he's ready to roll. He was out at the walk-through this morning and he's slated to do everything."