The Ohio State Buckeyes had a perfect season spoiled a year ago — and almost had the same thing happen a year earlier — by quarterback Juice Williams and Illinois.

Now, with so much to play for and so few games left, they’re taking steps to see that Williams and Co. don’t ruin yet another season when the teams meet in Champaign, Ill., on Saturday.

‘‘You never really forget things like that,’’ cornerback Malcolm Jenkins said of then-No. 1-ranked Ohio State’s 28-21 home loss to the Illini a year ago. ‘‘But it’s not the main focus of what we’re trying to do. We’re trying to get better.’’

So is Illinois. Coach Ron Zook’s team (5-5, 3-3 Big Ten) has foundered most of the season. The Illini need another win to clinch a bowl trip.

Ohio State (8-2, 5-1), meanwhile, still has high hopes of grabbing at least a piece of the conference title and of earning a Bowl Championship Series berth. They need to win out to accomplish both of those goals.

The Buckeyes barely escaped with a win the last time they played at Memorial Stadium in 2006. The nation’s No. 1 team struggled all day before pulling out a 17-10 win — one of the closest calls it had while rising to No. 1 during an unbeaten regular season.

Zook knows that the Buckeyes have taken a long look at the past couple of games with the Illini and are gearing up.

‘‘They’re obviously coming in here with a chip on their shoulder,’’ the Miami (Ohio) grad and former Ohio State assistant coach said. ‘‘We don’t have to worry about them looking past us to Michigan. They’re going to be zeroed right in on us.’’

In particular, the Buckeyes are zeroing in on Williams, a fleet runner who has developed into the Big Ten’s best passer. A year ago, Williams quieted the crowd at Ohio Stadium by passing for four touchdowns. Ohio State’s defense was giving up just 65 rushing yards a game, but with Williams performing sleight of hand the Illini shredded it for 260 yards on the ground.

This year, for the most part, he’s improved.

‘‘He can do it all. He can run, he’s throwing the ball better — which is hard to imagine since last year he threw the ball pretty well,’’ Ohio State linebacker James Laurinaitis said. ‘‘He’s grown so much. His decision-making has gotten better.’’

Williams continually bedeviled the Buckeyes in the fourth quarter. The Illini, protecting that 28-21 lead, ran more than 6 minutes off the clock at the start of the fourth quarter. After getting the ball back on Ohio State quarterback Todd Boeckman’s third interception of the day, the Illini took over at their own 24 with 8:09 to play — and never gave the ball back.

They ran 16 plays, picking up first downs on four third-down plays and another on fourth down.

It was a classic game of keepaway, with Williams all but taunting the Buckeyes by making just enough yardage to keep the seconds sifting away.

‘‘It was just frustrating,’’ Laurinaitis said. ‘‘You have to make those plays to get off (the field) on third down. To me, just looking back on that drive, (I remember) being frustrated, that we had to come up with a big stop and we couldn’t do it.’’

Many say that Ohio State doesn’t match up well with Williams because the Buckeyes defense has trouble with dual-threat quarterbacks. The one-sided losses in the last two BCS title games, the defeat to Illinois, losses earlier this season to Southern California and Penn State — in each case the opposing quarterback was mobile and could throw the ball.

Then again, others say, who doesn’t have problems with those types of quarterbacks? Maybe that’s why the Buckeyes have switched from the standard-issue, pocket-style Boeckman, to sleek, athletic freshman Terrelle Pryor, who is at his best when the play breaks down and he’s left to freelance.

Coach Jim Tressel said having a quarterback who can run freezes defenses and prevents them from being overly aggressive.

‘‘The quarterback that adds the problems is the one that can pull it down and run with it, which why Juice, he’s another dimension,’’ he said. ‘‘We haven’t faced anyone like him.’’

Except maybe in practice.

Ohio State’s defenders were stunned last season at how often they zoomed in for a tackle and grasped air instead of Williams. It’s something that will have to change this time around.

Jenkins said there are several ways to counteract Williams’ ability to evade tacklers.

‘‘Just being physical and winning up front and then getting them down when we can,’’ he said. ‘‘If we can do that, and eliminate big plays, we should be all right.’’