"He looked good on a limited basis," Reid said, according to The Athletic's Nate Taylor. "He took all the snaps and he feels good."
However, Mahomes still remains in the league's concussion protocol.
The 25-year-old - who's reportedly symptom-free - will undergo tolerance tests, according to NFL Network's Ian Rapoport. His workload in practice will increase throughout the week, Rapoport adds.
Mahomes suffered a concussion during the third quarter of Sunday's divisional-round win against the Cleveland Browns.
Meanwhile, running back Clyde Edwards-Helaire, cornerback Bashaud Breeland and wide receiver Sammy Watkins returned to practice. The rookie tailback hasn’t played since suffering a high-ankle sprain in Week 15, while Watkins has been inactive since leaving the team's matchup against the Atlanta Falcons with a calf injury. Similar to Mahomes, Breeland left last week's clash with a concussion.
Reid says Thursday will be a big day for all of the wounded Chiefs ahead of an all-important showdown for the AFC title against the Buffalo Bills.