Millsap had five points, four rebounds and two assists in 13 minutes before exiting.
The Nuggets signed Millsap to a three-year, $90 million deal shortly after free agency opened, and the move instantly boosted Denver's profile in a crowded Western Conference.
It also provided the up-and-coming Nuggets with a leader on and off the floor.
"Paul fits with the culture we're trying to create," head coach Michael Malone told Mile High Sports AM 1340. "When you have a locker room filled with so many young players, to add Paul, his experience and veteran leadership, it's a win-win for everybody."
Since arriving in Denver, the four-time All-Star has averaged 16.0 points, 6.3 rebounds, 3.1 assists, 1.1 steals and 1.3 blocks in a one-two frontcourt punch with center Nikola Jokic.
The last thing the Nuggets need is a lengthy absence from Millsap, but they do have the depth to withstand a short-term stint on the shelf.
Trey Lyles should be among the primary players called upon to pick up the slack in Millsap's stead.