Brewer sprained the thumb on Tuesday night during the second quarter of a game against the New York Knicks while diving for a loose ball. He had X-rays that came back negative. An MRI did not reveal any significant injury, and surgery was ruled out.
Brewer said Tuesday that he is determined to play in Game 1 of the playoffs against the Indiana Pacers on Saturday.
"As long as [the thumb's] still on my hand, I'm still going to play, regardless," Brewer said before Wednesday's game. "You have nicks and bruises, it comes with the territory. I think we're in a great situation to do something special and it would have to take something serious to keep me out."
Brewer also added that he would tape the thumb before playing but wouldn't use a protective device.
Bulls vice president of basketball operations John Paxson told ESPN 1000's "Carmen, Jurko and Harry" show Wednesday that the organization is "encouraged" by where things stand with Brewer.
"He did get an MRI today, and he's seen the hand specialist and all," Paxson said. "Definitively we don't have an answer yet, but we're optimistic that he's going to be fine for the playoffs."
Noah tweaked his already sprained right ankle on Tuesday during the fourth quarter, but he said he felt fine.
"I'm fine," Noah said after scoring 10 points and grabbing 10 boards in 23 minutes Wednesday. "This is so exciting right now. I think that once you step onto the court you're numb to all that stuff."
Nick Friedell covers the Bulls for ESPNChicago.com and ESPN 1000.