CHICAGO -- While the Chicago Bulls continue to operate on the premise that Jimmy Butler will need a week for his left thumb injury to heal, coach Tom Thibodeau will move forward as if he won’t have one of his top defenders for the season opener.

Butler injured his left thumb in the first quarter of Sunday’s preseason game against the Charlotte Hornets. An MRI on Tuesday confirmed that he has sprained ligaments in the thumb on his non-shooting hand.

If Butler remains on his one-week timetable, he would be ready to play in the Oct. 29 season opener at New York against the Knicks. Thibodeau will believe it when he sees it, though.

“Obviously, I’d prefer to have him, but if we don’t, we don’t,” Thibodeau said after practice Wednesday. “We have more than enough. Next guy step up, get in there, get the job done. That’s why you have 14 guys. You prepare for everything.

“An injury can happen at any time. That’s why it’s so important for everyone to be ready. Even though you may not start off in the rotation, when that time comes you have to be ready. I think we have the type of guys that will be ready.”

Kirk Hinrich could start at guard opposite Derrick Rose in the final preseason game Friday against Minnesota at St. Louis. In the short term, the injury could mean additional minutes for guys like Aaron Brooks and even Tony Snell.

What obviously bodes well for the Bulls is that Butler is a right-handed shooter. It also doesn’t hurt that the Marquette product entered training camp in excellent shape.

“That’s why it’s so important to be in great shape; people lose sight of that,” Thibodeau said. “If you come in in average or below average shape and then you take on an injury, now you’re in deep trouble. If you’re in great shape, usually that helps you overcome a lot. Really the only way to get in great shape is to work. There’s no getting around that.”