Barnes (head) went back to the locker room in the fourth quarter of Monday's game against the Nuggets, Aaron Rose of SI.com reports.
The forward caught an elbow to the face from Nikola Jokic and was assisted to the locker room. Barnes is not expected to return with the game nearing its end, and he contributed 21 points (9-19 FG, 1-3 3Pt, 2-4 FT), 11 rebounds, nine assists, five steals and a block across 35 minutes.