Updated

If anyone gets the idea that being unbeaten and No. 1 means life is all sunshine and lollipops for Ohio State coach Thad Matta, think again.

Matta worries about everything. He worries about opponents, of course, but more about what's going on in the heads and hearts of his own players. Oh, and he also worries about the weather, food, injuries, conditioning, academics, defense, offense and a thousand other things.

Whether a team is 21-0, as are the Buckeyes, or 0-21, to Matta there is always something lurking out there that can get in the way of winning the next game. That was evident by a recent exchange between the Ohio State basketball and football coaches.

"Coach (Jim) Tressel and I were texting a week or so ago," Matta said Friday. "I can't remember what he said, but I said, 'Be thankful you've only got 13 of these.'"

For meticulous, micro-managers like Matta, there is never anything so small that it couldn't screw up a game or season. He is constantly on the lookout for the next impediment to a win.

"It's 'How much rest? Are they getting the right nutrition?'" Matta said of his players. "You're trying everything that you can. I was nervous before the Illinois game because we ate bar food at Hoolihan's. I'm looking over and saying, 'This can't be good.' But I guess we were OK."

Yes, the Buckeyes (8-0 Big Ten), the last Division I unbeaten, have been OK, to say the least. They overcame the chili-cheese fries and chicken fingers to win at No. 23 Illinois, 73-68. They've won close games against not-so-good teams and then they've rolled past quality opponents such as No. 12 Purdue, which they routed 87-64 on Tuesday night.

Next up is Northwestern. The Wildcats (13-7, 3-6) may not look imposing to a lot of fans, but they're downright scary — particularly when playing at home — to Ohio State.

After all, they've been told by Matta that every opponent is a contender, every player on the other team can embarrass you and every lackadaisical effort is an opportunity for a defeat.

Freshman Deshaun Thomas, instant offense for the Buckeyes off the bench, has been taught to trust nothing but hard work and your teammates.

"I learned from what coach Matta said, 'Don't worry about what everybody says that is good,'" he said. "We're trying to win a national championship. We've got to get there. That's our goal."

Matta, perhaps mirroring the fears that he has put in his players, says they've told him how dangerous Northwestern can be.

"Our guys said it — the last time we played there we lost on a last-second shot," he said, referring to a 72-69 loss at Welsh-Ryan Arena on Feb. 18, 2009. "Our guys have tremendous respect (for them). Honestly, now that we've been through this and we've had the ups and downs throughout the course of games, our guys understand now that this is for real: On any given night, if we don't play well, we're not going to like the outcome."

The coach and his Buckeyes aren't taking the Wildcats lightly even though they might be without their best player. John Shurna — fourth in the Big Ten in scoring at 19 points a game — suffered a head injury when he was knocked into the basket support during a loss to Minnesota on Wednesday night.

He returned to the game after the injury, but in these days of heightened awareness of concussions no one knows for certain if he'll be available on Saturday night.

"He said he just didn't feel right," Northwestern coach Bill Carmody said.

It was Shurna who hit that last-second shot — actually a fallaway 3-pointer with 3.3 seconds left — to beat the Buckeyes the last time they went to Evanston, Ill. Carmody said at Friday's practice that Shurna's availability would be determined on Saturday.

In a year of upsets in the Big Ten, Matta doesn't have to remind his players about what happens on a night when one team overlooks another, or when the underdog has a hot hand.

"We appreciate it," shooting guard William Buford said of the Buckeyes' perfect record. "If we didn't appreciate it, I think we would stop working as hard as we are right now. We'd just be complacent. But we're not doing that."

Matta did a round of media interviews by telephone on Thursday. What he heard back from reporters was how good his team is, how invincible they should be against certain teams. Then he met with his players and warned them not to fall for any of it.

"It's one of those things that that comes with the territory and you'd better handle it," he said. "I said, 'We can't change who we are. Let's just be who we are, have a good practice and get ready for Northwestern.' I think they understand what I'm saying."

(This version CORRECTS UPDATES with Shurna as game-day decision; corrects to Deshaun Thomas instead of Coleman.)