"And now, for some real competition.

After dismantling the lowly Nets, Hornets and Bobcats to improve to 6-2 on their season-high, nine-game trip, the Bulls close against the Celtics in Sunday's high-profile matinee.

And they may do so again without Derrick Rose, whose sore back prevented him from making his customary "I'm fine" or "I'm playing" declarations when asked before Saturday's film session and walk-through at a local college.

"I really don't know," Rose said about playing Sunday. "When I wake up, I usually can tell. … It's just sore and stiff. I don't know what to do. Hopefully it will heal in a matter of time."

After sounding optimistic at Friday's morning shootaround in Charlotte that he would play against the Bobcats, Rose sat. C.J. Watson later revealed to reporters he knew Thursday that he would start for Rose but wouldn't offer a similar statement Saturday.

With toe and now back issues, Rose has missed six games, matching his total from his first three seasons combined. He also sat for the second half of Monday's victory in New Jersey.

"This is the most I've ever been injured," Rose said. "It's frustrating knowing I worked so hard. Hopefully I'll be back soon. I hate missing games, especially against great teams."

The Celtics no longer may be great, although they had reeled off nine victories in 10 games before dropping two straight to the Lakers — in overtime — and Raptors. But in comparison to recent competition, players are excited for the test."