Collins didn't return for the second half, as the Hawks trailed 58-55. Before exiting, he tallied 13 points and three rebounds in 13 minutes.
Collins was hit in the head and left the court, thinking he earned his third foul of the night, but when the foul was swapped to someone else, he returned despite the injury, according to Cleveland.com's Chris Fedor.
The 23-year-old is averaging 17.6 points on 53.1 percent shooting, with 7.5 rebounds in 31.5 minutes per game.
After he turned down an extension worth more than $90 million, the Hawks had "shown a willingness to listen to offers for Collins," though the necessity of having him on the team alongside Trae Young and Clint Capela made the Hawks "unlikely" to move him, according to Sam Amick of The Athletic.
Danilo Gallinari started the second half in place of Collins. The veteran is averaging 10.7 points on 37.6 percent shooting through 20 minutes per game. Solomon Hill could also factor into the team's plans if Collins ends up being sidelined with a concussion.
Hill is tallying 4.5 points per game in an average of 18.8 minutes.