But coach Andy Reid said Monday the Chiefs aren't certain whether they will be able to go with Mahomes or have to use veteran backup Chad Henne at quarterback on Sunday.
"He mentioned it to you that he's going to play. That's his mindset, and then we'll just take it day by day and see how he does.''
The Chiefs' first practice this week is on Wednesday. Reid said he wasn't sure whether Mahomes would be available to work then.
"I've got to see how he feels when we get ready to practice,'' he said.
As for whether Mahomes could play against the Bengals without practicing all week, Reid said, "Yeah, I think so. He's never done that, so I don't know. I don't have the answer for you on that.''
Mahomes' mobility was limited and his style of play changed dramatically after he returned to the game in the second half on Saturday. He threw no passes outside of the pocket, according to NFL Next Gen Stats, marking only his second half this season in which he made all of his throws from the pocket.
He led the NFL during the regular season with 113 throws from outside the pocket.
Reid said he was expecting the Bengals to put pressure on Mahomes beyond what they normally might because of his limited mobility.
"I'm sure they'll do something, yeah,'' Reid said. "But I'm not going to chase a bunch of different things. We should have things covered in our protections no matter what.''