The team announced that Mahomes was ruled out for the remainder of the game. The quarterback went down with the injury with about 10 minutes left in the second quarter after a fourth-down quarterback sneak.
The Chiefs' medical staff attended to Mahomes on the field before he waved off the cart and walked to the locker room. League sources told NFL Media that he was taken for X-rays and subsequently declared out.
Backup quarterback Matt Moore entered the game for Mahomes with the Chiefs leading 10-6. Mahomes finished with 76 yards and one touchdown on 10-of-11 passing.
The Chiefs held a 20-6 lead over the Broncos at halftime. Midway through the third quarter, Moore completed 7-of-13 passes for 33 yards.