Ohio State will seek its fourth straight win when it faces struggling No. 18 Illinois on Sunday afternoon in Champaign, Ill.The Buckeyes (13-8, 5-5 Big Ten) have turned around their season with strong defense and the guard play of John Mobley Jr. and Bruce Thornton.It’s been a good stretch for Ohio State.After upsetting then-No. 11 Purdue on Jan. 21, the Buckeyes posted consecutive routs of Iowa (82-65 score) on Monday and at Penn State (83-64) on Thursday.”That’s two games in a row that defensively we have been dialed in and really done a good job, and I think two games in a row we’ve rebounded really well now,” Ohio State coach Jake Diebler said.”You’ve got to know that every single game you can’t sit and be too happy on your performance. We’ll celebrate this one, and then we’ve got to turn the page quickly. I’m proud of our guys for battling. That’s now two straight road games. We’ve got another tough one here coming up.”Illinois (14-7, 6-5) has not been able to overcome the absence of center Tomislav Ivisic, who has missed the past three games due to mononucleosis.That was never more evident than during an 80-74 overtime loss Thursday to a Nebraska team that had lost six straight.Illini coach Brad Underwood criticized his players’ shot selection.”Stunk. It’s terrible,” he said. “But that’s part of the problem, not having Tomi, and that’s one of the things that we’ve got to get figured out, because I have no idea when we get him back.”Ivisic has averaged 13 points and 8.5 rebounds in 18 games this season.”It’s big, for sure,” sophomore guard Dra Gibbs-Lawhorn said of not having Ivisic. “Tomi is a great player. He’s one of our starting guys, one of our best players for sure. That’s not an excuse. We have to have the next-man-up mentality.”