Not much gets by Jeff Brohm on the practice field.

Purdue’s 4th-year coach is involved in nearly every aspect of the Boilermakers’ game-planning, especially on the offensive side. So in any given practice over the years, he can be seen jumping from position to position to make sure his offense — and it’s definitely his — is as finely tuned as possible. One moment, he’s laying into a wide receiver for running a route too far outside the hashes that results in a catch out of bounds. The next moment he’s calling the next play. Then, he’s lamenting his quarterback’s bad decision. Sure, he might mix in an encouraging word toward a tight end or offensive lineman (or even a QB), but those are more rare.

Brohm is fiery, intense and focused and keen on winning. Mild-mannered, it seems, off the field, he’s turned up to 11 on the practice field.

But this week, Brohm will have all of that turned off, and boy is that a huge change for the Boilermakers. The man so integral to Purdue — he’s not only the head coach, but the team’s play-caller and, in many ways, its emotional barometer — will be sidelined this week after testing COVID-19 positive. It’s possible, if not likely, that he’ll be out for Saturday’s opener against Iowa in Ross-Ade Stadium.

In an adverse 2020, Purdue will be faced with a ton more of it Saturday. During a Zoom interview Monday, Brohm said he’ll isolate after experiencing some symptoms and he’s has had other family members suffer through the same. So, above everything else, he needs to get healthy; no return to Purdue will happen before that.

Brohm is only the latest coach to test positive for COVID-19, joining Alabama’s Nick Saban, Arizona’s Kevin Sumlin and a few others, but they returned to their teams. (Saban’s test result was a false positive.) Kansas coach Les Miles, who had also tested positive, skipped the Jayhawks’ game Saturday out of an abundance of caution, staying home despite a negative test because he was still in his 10-day isolation window.

It remains to be seen what the next several days will bring Brohm, but Purdue is planning to go ahead without him. Brohm says he’ll do as much as he can from home, located less than a mile north of his office at Purdue’s football facility.

Others, meanwhile, will take over hands day-to-day activities.

Younger brother Brian Brohm will serve as the acting head coach Saturday if Jeff isn’t able to be at the game. Although siblings — with a 14-year age gap — they couldn’t be more different. Both are competitive, as can be seen by their successful careers as quarterbacks at Louisville, but that manifests differently. Brian, a co-offensive coordinator and QB coach, is a much quieter, calmer presence, a demeanor that has played well as against Jeff’s more in-your-face approach. It likely was a relief for David Blough or Elijah Sindelar to get gentler feedback from Brian on the sideline after feeling the wrath of Jeff immediately coming off the field. If Brian’s on the sideline, rather than in the press box, for the Hawkeyes on Saturday, it’ll be a different look, one that the Boilermakers will have to adapt to.

JaMarcus Shephard, the wide receivers coach, has a co-coordinator title, as well, so he possibly could see an increase in game-day duties.

Not much will change, though, defensively. Bob Diaco, the only assistant on Brohm’s staff with major FBS head coaching experience, after his stint at UConn, might have been a possibility for “acting” head coach duties. But considering his only months into his tenure as Purdue’s new defensive coordinator, a role he shares with assistant Anthony Poindexter, he’ll be able to continue to focus on only his side of the ball. Probably a good thing, considering he’s installing his own scheme, one that calls for a variable-front defense, often 3-4, that differs from what Purdue has traditionally run.

So now the Boilermakers move on, with only a handful of days remaining til the opener, in a season that they hope represents a significant step forward in the Brohm Era. For Purdue to get there, though, it just might have to without the man himself on the sidelines for Game 1.