Mahomes, who is also dealing with a foot issue, is expected to return to practice Wednesday, adds Schefter.
The star passer left Sunday's divisional-round playoff game against the Cleveland Browns with an apparent concussion.
Mahomes passed for 255 yards and a touchdown before exiting Sunday, adding 14 yards and a score on the ground. The Chiefs earned their third straight AFC Championship Game appearance thanks to some late-game heroics from backup quarterback Chad Henne.
Kansas City hopes to see Mahomes under center for Sunday's AFC Championship game against the Buffalo Bills, but Schefter notes nothing is certain at this time. Mahomes, 25, propelled the Chiefs' offense with two touchdowns, 225 passing yards, and 36 yards on the ground in a 26-17 win when the two teams met in Week 6.
The Chiefs will try to book their trip to Super Bowl LV on Sunday with a win over a Bills squad that hasn't lost since Week 10.