Following the defense’s total collapse against Indiana, Northwestern defensive end Napoleon Harris and linebacker Billy Silva lamented that they had expected Hoosiers quarterback Antwaan Randle El to “option, option, option.”

This explanation provided some logic for what happened — Randle El surprised the Wildcats for 246 yards and three touchdowns in the air in NU’s 56-21 loss.

But head coach Randy Walker wasn’t buying the excuse that seemed to pin responsibility for Saturday’s loss on his defensive coaching staff.

So Silva recanted — sort of.

“After the game, I guess when we said all we did was prepare for the option, I think that was just because the contrast between our practice and the game was so stark,” Silva said. “In practice, a lot of it was option, but we saw a bunch of different looks.”

Defensive coordinator Jerry Brown was also taken aback by the excuse this week. But he softly declined to berate his players.

The subtle disagreement has compounded the team’s frustration this week. And so it’s Brown, caught in the middle, who carries most of the load in trying to right the defense for the Cats’ final three games.

His strategy for the stretch run reflects Walker’s new philosophy that the coaching staff’s job is not to coddle the players, but to kick them in the pants. Brown won’t be changing any lineups or formations. He’ll just be pushing his players’ buttons a little harder.

“It’s a catch-22 this late in the season,” he said. “You try to get your guys to go after one another a little bit more aggressively.

“But at this late stage there’s a lot of guys who are nicked up, and the more you hit them, the more nicked up they become. We talked with the coaching staff and that’s a risk we have to take right now.”

Brown knows that the criticism of his defense has intensified this season. Although the Cats’ numbers aren’t substantially different from last season — in fact, the team is on pace to give up fewer yards in the air in 2001 — losing changes everything.

And the defense hasn’t been able to hide behind the nearly 40-point-per-game offense that obscured so many flaws last season.

“If you’re going to be a good defense, you’ve got to stop the rush, and we haven’t done a good job of doing that,” Brown said. “You wear a bull’s eye when you don’t do those things. That’s just the nature of the game and I understand that. I don’t like it, but I deal with it.”

As a unit, the defense may not be the only one sporting a target on its back.

The only coach on the staff to predate Walker’s arrival three years ago, Brown may have to take the fall for the defense’s gaffes this season.

Former defensive end Conrad Emmerich said it wouldn’t surprise him if coaching changes over the offseason left Brown without a job at NU.

“I don’t know if it seems fair or not,” said Emmerich, who graduated last year. “I think that’s just the nature of the game. They always point the finger at someone for a bigger organization’s fall. The defense is struggling and who heads up the defense? Not beating around the bush, Jerry Brown.”

Walker said such personnel decisions haven’t entered his mind this early in the year, and the team’s performance won’t be fully evaluated until January or February.

Firing Brown wouldn’t be a solution to the defensive woes, said Emmerich, who also referred to the 51-year-old coach as one of the most respected members of NU’s staff.

Before becoming a co-defensive coordinator in 1997, Brown took the job as the Cats’ defensive backs coach in 1993. His leadership with the secondary helped NU become No. 1 in the country in scoring defense during the 1995 Rose Bowl season.

Silva agreed that Brown has been a positive force on the defense and said players haven’t lost confidence in the coach, even as the disappointing season has unfolded.

“He’s a great leader, he’s always there and he motivates us,” Silva said. “He’s constantly talking to us after practice and letting us know what we need to do.”

Brown, for his part, is focussed on the final three games. Anything else — the criticism, the finger-pointing and his job security — will be out of his control.

“That’s the business I’m in — if it happens, it happens, and there won’t be a whole lot I can do about it,” Brown said, adding that he doesn’t have a contingency plan. “I’ve always been wanting to enjoy the job I’m in. I haven’t been wanting to look for the next job. It’s just not in my nature.”