Doncic injured the ankle with 44 seconds remaining after contesting a driving layup by Nuggets guard Austin Rivers, who fell onto Doncic's leg.
Doncic immediately hobbled to an empty courtside seat, sitting down and clutching his left ankle, before limping to the locker room.
"Luka walked off on his own power," Dallas coach Jason Kidd said. "I think he got rolled up on his lower left leg, so we'll see how he feels tomorrow."
Doncic was not made available to the media postgame because he was receiving treatment on the ankle.
Doncic has a history of ankle sprains. He missed a total of 11 games during the 2019-20 season due to right ankle sprains. He played the last three games of the Mavs' 2020 playoff series despite a left ankle sprain.
Doncic, a first-team All-NBA selection the past two years, is averaging 24.9 points, 8.3 rebounds and 7.9 assists per game for the 9-4 Mavs.