Wood, competing with Bob Howry and Carlos Marmol for the spot, was to throw one inning Wednesday and again on Thursday. That plan is on hold now, and the Cubs will delay an announcement as to who has the job until Wood can go on consecutive days.
"It's a little bit of a setback but nothing, nothing serious," Cubs manager Lou Piniella said Wednesday. "It's a minor thing he goes through every spring."
The Cubs play at Tucson on Friday, and they don't want Wood pitching Thursday and then having to sit on a bus for the two-hour ride down Interstate 10 for one inning. He most likely won't throw until Saturday, when the Cubs play host to the Chicago White Sox.
The only question about whether Wood could handle the job is if the right-hander is durable enough. He's been slowed the last few years because of problems with his shoulder. Does this make Piniella re-think whether Wood can be the closer?
"No," Piniella said. "Remember, we have three people here who, in my mind, can close and I'm very comfortable with. A bad back doesn't change my plans, but we still want to see him throw back to back and have him pitch an inning-plus. The process was going to start today and now it's been delayed by hopefully a day or two at most."
Wood's back was a little stiff on Tuesday, and it was worse on Wednesday. He did not see a specialist, but received treatment from the Cubs' medical staff. A team spokesman said Wood wanted to pitch on Wednesday, but was held back as a precautionary measure.
Meanwhile, Kosuke Fukudome was in the lineup on Wednesday for the Cubs' game against Oakland. He had no lingering problems after getting hit in the side of the neck by a thrown ball while trying to steal a base on Tuesday.
Alex Cintron, however, will be sidelined a few days because of a sore left hamstring that forced him out of Tuesday's game.
"He's not available today," Piniella said of the infielder. "They don't think it's a pull; our trainer seems to think we'll have him out there in the next few days."
The Cubs have had their share of freak injuries, such as Mark DeRosa's irregular heartbeat. Is Piniella concerned?
"If we had to be concerned about everything to be concerned about, we'd never sleep around here," Piniella said. "It's just a stiff back [for Wood] and nothing more, and it could happen to anybody. That's why we have seven pitchers in the bullpen. That's why we'll carry a long reliever, so if a starter comes to the ballpark and can't start that day, we'll have a starter in his place. This is why you have 13 position players as opposed to eight or nine. Things happen.
"With Kerry, I was looking forward to seeing him pitch today and tomorrow, and getting that obstacle out of the way, but now we'll have to wait a couple days," he said.
Carrie Muskat is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.