A source told ESPN's Adam Schefter that Maclin has a high ankle sprain.
The Chiefs, who extended their NFL-best winning streak to 11 games, will face New England on Saturday.
Maclin suffered the injury during the third quarter and left on a cart in tears. The Chiefs initially feared that Maclin had hurt his knee ligament, which he has had surgically repaired twice. That it was an ankle injury provides some hope he'll play again in the playoffs.
Maclin missed a game against Pittsburgh earlier this season with a concussion, and rookie Chris Conley had six receptions in his place. Conley also replaced him for the remainder of Saturday's game against Houston, and caught a touchdown pass on a play that was designed with Maclin in mind.
Without Maclin, the Chiefs would lose by far their top downfield threat. The veteran had 87 receptions for 1,088 yards and eight touchdowns this season, while Conley managed just 17 catches for 119 yards and a touchdown.
Maclin's absence would also deprive Alex Smith of his biggest safety blanket. Whenever things go awry, the Chiefs quarterback has a tendency to look in Maclin's direction.
Yet playing without key players has become one of the hallmarks of this team. They lost electrifying running back Jamaal Charles to a season-ending knee injury in Week 5, and journeymen Charcandrick West and Spencer Ware filled in admirably.
Ditto for injuries to nickelback Phillip Gaines and a litany of offensive linemen who have gone down, including center Mitch Morse, who missed Saturday's game with a concussion, and right guard Laurent Duvernay-Tardif, who sustained a concussion during the game.
Information from The Associated Press was used in this report.