The team leader in tackles and an initial semifinalist for the Butkus Award, the junior was ruled out for this weekend's game due to a hurt shoulder.
How does the defensive staff plan to fill Brown's role?
"By committee to be honest with you," defensive coordinator Tim Banks said.
Those instances were in different circumstances because Brown was still able to play, taking some pressure off the young Svetina. This weekend, Brown's not trotting out on the field for the second series, something that Svetina says doesn't alter his mindset.
"I'll just be getting more snaps, and that's really the only thing that's changed," he said.
His insertion into the starting lineup against Wisconsin and Michigan was partly because of a high-ankle sprain suffered by sophomore Houston Bates, who started alongside Brown in the first two games of the season.
Bates says he's near 100 percent, so he'll see time this weekend and could potentially start.
"Somebody's got to step up. We realize that," he said.
Bates and Svetina are the most likely candidates to start, but Banks threw another name into the competition earlier this week.
"Ralph Cooper is going to have to step up," he said.
A sophomore with 12 tackles on the year, Cooper has appeared in every game and had a team leading six tackles against Charleston Southern.
Bates' health and Cooper becoming more dependable are crucial for a defense that otherwise will be playing two freshman at linebacker Saturday.
"I don't know if that's the case at too many BCS schools, but it is here," coach Tim Beckman said. "It was last week against Ohio State when Jonathan when down."
As an added measure, senior fullback Zach Becker was moved to linebacker this week, the position he originally walked on the team to play.
"Defense was always my love of the game," Becker said. "That's what I walked on as. Even though there's only three games left, I'm still going to make the most of it and playing as hard as I can. I'm having fun doing it."
Regardless of who starts, Banks and Beckman were clear that one player wasn't going to replace Brown. It's going to take a group.
"I think everybody understands that Jonathan's a great player and he's going to be missed, but at the same time it's another opportunity for somebody to step up," Banks said.