Noah didn't participate in the morning shootaround Wednesday as swelling returned to the ankle overnight after he went through most of practice Tuesday.
"My ankle's really swollen and it's painful right now so I'm just trying to get ready for the next game," Noah said. "I tried to go earlier but I couldn't cut or anything like that."
Noah, who hurt the ankle in the fourth quarter against Philadelphia on Monday night, is uncertain if he'll play Friday at Detroit.
"We'll see," he said. "I'm just trying to take it day by day. See how it feels [Thursday] in practice and we'll see how it feels Friday."
Noah said he had no regrets about practicing on the ankle on Tuesday.
"The trainer said whether I practiced or not wouldn't make a difference on my ankle," Noah said. "It feels better."
Kurt Thomas started in Noah's place.
Nick Friedell covers the Bulls for ESPNChicago.com and ESPN 1000.