Derrick Rose missed his fourth straight game with back spasms but looked as pain-free as he has in several weeks while warming up before Thursday night's game with the Celtics.

"We want him to be pain free," Bulls coach Tom Thibodeau said. "He's very close."

Rose shot free-throws earlier Thursday but was unable to run.

"I know that it's going to be sore a little bit but I know that I don't want to deal with it during the games where it gets tight and it gets irritated,"Rose said. "I'm going to come back when I'm ready."

Rose said he wasn't in any pain after shootaround and had two treatment sessions scheduled --- one at the Berto Center after shootaround and another when he arrived at the United Center.

He also reported that his back tends to spasm during activity only.

"If I'm just sitting around I don't really feel it like that but when I'm out there doing something that's when it usually bothers me," he said.

Rose has been seeing a back specialist for hour-long sessions that he vaguely described as a stretching routine.

He also said he's learning that some injuries he can play with while it's better to rest others.

"The back is totally different where with an ankle, you can kind of play through that," he said. "As a guard you're used to twisting your ankle. It's my second time in my life dealing with this and it's quite different.