He is not expected to miss much time, but it marks the second game in less than a week that he will be out. He sat out Saturday's victory over the Milwaukee Bucks because of left knee soreness.
Over the past few days, Bulls coach Tom Thibodeau has been asked several times about the possibility of rookie Doug McDermott beginning the season in the starting lineup. McDermott played well in Dunleavy's place on Saturday and is expected to start on Thursday as well.
Thibodeau remains noncommittal about starting McDermott, but it's clear that the thought has run through his mind.
"I don't want to overlook what Mike's done, either," Thibodeau said after Thursday's shootaround. "Mike has shot the ball extremely well. I think he helps that first unit function well. I'm not locked into it, but I don't want to ... Mike's team defense is outstanding. I don't want to overlook that. You have to think about [how McDermott would be] guarding a starter now, so that does make it different. That's the great value of Mike -- he's started before, he's come off the bench, he's comfortable in both roles.
"He's got a great motor, he doesn't need a long time to warm up. But I liked the way he played last year as a starter for us a lot, so I don't want to make that decision yet. We'll see how it unfolds."
The key for Thibodeau is that if he elevates McDermott into the starting role, he could solidify his bench group with Dunleavy playing alongside Kirk Hinrich and Taj Gibson. Dunleavy played in all 82 regular season games last year. He started 61 games with Jimmy Butler dealing with injuries early in the season and after the Luol Deng trade in January.
Dunleavy's presence off the bench would also mean that Thibodeau wouldn't be leaning on a second unit that would have two rookies with McDermott and Nikola Mirotic.
Thibodeau says he still isn't sure what he will do, but if McDermott shows he can pick up the defensive schemes quickly, it might be best long-term for Thibodeau to leave McDermott with the starters and allow his game to grow that way.
Rose and Noah improving: Thibodeau would not reveal whether Joakim Noah and Derrick Rose will play more than about 20 minutes, as they did in Milwaukee on Saturday, but he seems happy with their progression.
"As long as they continue to get better, that's the big thing," Thibodeau said. "Have good timing, practice well, play well. Hopefully it will all work out."
Does Thibodeau see improvement from the pair over the past few weeks?
"They're definitely moving in the right direction," he said. "They've just got to keep working at it and the more they're on the floor together the better it's going to get. The same thing -- they have to get used to playing with Pau and the entire group. Each day's a little bit better."