In their final preseason game, the Bulls also lost forward Tyrus Thomas in the third quarter with a right foot injury and rookie forward Joakim Noah went down in the fourth quarter with what looked to be a right ankle injury. Neither player returned to the game.
Wallace's injury came when Hinrich scored on a driving layup with 9.1 seconds left in the second quarter. Wallace, who was battling for position with Bucks center Dan Gadzuric, got his foot tangled up with Gadzuric's and fell to the floor. Wallace stayed on the floor for the final nine seconds holding his left ankle.
Wallace was treated by a team trainer and limped to the locker room with the assistance of a team trainer and Chris Duhon.
The Bulls (4-3) led 52-43 at the half, and then outscored the Bucks 14-6 to start the third quarter. Ben Gordon hit a 3-pointer to start the run and Hinrich added another 3-pointer to give the Bulls a 66-49 lead early in the third quarter.
Gordon played in his second game after missing the first five exhibition games with a sprained left ankle. He finished with 11 points in 24 minutes. The Bulls also had Luol Deng back, who missed the past two games with a right wrist contusion. Deng finished with 12 points.
Bucks starters Andrew Bogut, Michael Redd and Mo Williams missed the game. Bogut has a sprained left wrist, while Williams and Redd had the night off. The Bucks play their final preseason game on Friday at Minnesota.
Bogut's status is listed as day to day, and it's not yet decided whether Bogut will play in Milwaukee's regular-season opener on Oct. 31 in Orlando.