Reid said Mahomes' passing hand, which was injured when he fell awkwardly early in Sunday's win over the New England Patriots, was "bruised up pretty good, but there's no break in it."
Mahomes played the entire game, and he and Reid said afterward that there was no serious consideration given to removing him from the game. The Chiefs went with more of a shorter passing game after the injury, though Mahomes was able to throw a 48-yard touchdown pass to Mecole Hardman.
"He was having a little tougher time gripping the ball, so we went with a little bit more of a shallow cross game [and] shorter throws," Reid said. "We ran the ball a little more, probably."
Mahomes was 26-of-40 for 283 yards and the touchdown to Hardman. The Chiefs scored only a field goal in the second half.
The Chiefs have clinched the AFC West championship but still have plenty to gain by winning Sunday against the Denver Broncos at Arrowhead Stadium. The Chiefs are one game behind the Patriots for the AFC's No. 2 playoff seed, which includes a first-round bye.
Reid said the Chiefs wouldn't rest Mahomes just because he might not be 100 percent against the Broncos.
"He could still be effective," Reid said. "[The injury] is not an excuse for the second half."