In more ways than one, Purdue has surprised in the first 5 games of the season.

Its defense is much better than expected, as the Boilermakers rank third in the Big Ten in scoring defense, allowing only 15.4 points per game. Its offense, however, is the opposite, as the Boilermakers are scoring only 23.6 points per game, fourth-worst in the conference.

As Purdue (3-2) gets set to travel to likely No. 2 Iowa on Saturday, its first game after the bye, let’s take a look at what we know and what we don’t know about the Boilermakers.

5 things we know

Red zone woes

The Boilermakers are atrocious in the red zone, the biggest reason why they’ve scored only 13 points in each of their last 3 games.

Purdue ranks No. 12 in touchdown conversation rate from inside the opponents’ 20-yard line, finding pay dirt in only 10 of its 21 trips (47.6 percent). The mark ranks better than only Wisconsin and Illinois. The Boilermakers have scored 7 field goals, raising their overall red zone scoring percentage to nearly 81, good for 7th in the Big Ten.

But Purdue, like everyone else, wants 7-pointers, not 3s, and it’s not getting them. In the loss to Minnesota more than a week ago, the Boilermakers were in the red zone 4 times, scoring a touchdown once but three times settling for FG attempts, one of which was missed.

The QBs are what they are

Each of Purdue’s 2 quarterbacks — Aidan O’Connell and Jack Plummer — has strengths, but each has glaring weaknesses, too.

And the erratic quarterback play is preventing the Boilermakers’ offense from clicking (although a lack of a running game hurts, as well).

Plummer started the Boilermakers first 4 games, and although he didn’t turn the ball over, he didn’t move the offense either, especially against Notre Dame and Illinois. The junior wasn’t getting the ball down the field, likely in part because defenses didn’t respect Purdue’s ability to run the ball and could sit back to prevent big plays.

O’Connell is more daring, which has led to turnovers, but his willingness to try to force the ball into tight quarters has helped the Boilermakers move the football, at least between the 20s. O’Connell, a senior, is likely to get another chance at Iowa, but Purdue’s QB rotation might not yet be over this season.

Horvath is important

When Zander Horvath was injured in Purdue’s Week 2 blowout win at UConn, some thought the Boilermakers would be able to overcome the loss of their starting running back.

They were wrong.

Since Horvath broke his leg, the running game has largely been stuck in the mud, as Purdue is averaging only 88 yards rushing per game, not only the worst in the Big Ten but the worst by nearly 34 yards per game. That Purdue played one game, against Illinois, without capable backup King Doerue exacerbated the issue.

Horvath, a big 6-3, 230-pounder, is a bruiser between the tackles, capable of wearing down a defense and being effective in short yardage and in the red zone. His loss was a huge one for the Boilermakers. He’s likely to come back this season, but likely not until Wisconsin next week, at the very earliest.

Defense gets an A

Purdue’s defense has been outstanding, especially in context, given that Jeff Brohm completely changed over his defensive staff in the offseason.

Gone is the bizarro bend-but-don’t-break Bob Diaco mess of 2020, which didn’t play to Purdue’s personnel or its personality. And in is Brad Lambert’s aggressive, in-your-face defense that the Boilermakers have embraced. Lambert’s crew — the former Marshall DC is a co-coordinator and play-caller at Purdue — is third in the Big Ten in yardage allowed, giving up only 297 per game, and is No. 1 in the league in pass D, allowing only 175 per outing. Even though Purdue’s not racking up a ton of sacks, only 7, it’s creating pressures on opposing quarterbacks.

The Boilermakers also need to force more turnovers, because they’ve had only 2 interceptions and no fumble recoveries, but if they keep being aggressive, it seems likely that those will come.

6 is important

After missing a bowl in back-to-back seasons, it’s imperative that the Boilermakers find their way back to the postseason in Brohm’s 5th year in West Lafayette.

There’s still a path to get to 6 victories, although it narrowed after the loss to the Golden Gophers on Homecoming.

Purdue has what feel like toss-up games vs. Wisconsin and Indiana in Ross-Ade Stadium, plus a date in Wrigley Field against Northwestern. The Boilermakers also play at Nebraska, a sub-.500 team that has likely performed better than its record but hasn’t been able to finish. Purdue will be an underdog at Iowa and Ohio State and vs. Michigan State.

5 things we don’t know

Get healthy?

At one point in the first half of this season, Purdue was without its top wide receiver in David Bell, his backup (Mershawn Rice), its top tight end in Payne Durham, the No. 1 cornerback in Cory Trice and Horvath, the top running back. And a number of other key backups were out, as well.

Of the top-line group, only Bell has returned; he’s back out of concussion protocol after missing the Illinois game. Purdue hopes to get Durham back for Iowa, if he can get out of protocol. Trice was dressed vs. Minnesota, after suffering an ankle injury earlier in the season, but didn’t play. Maybe he’ll go vs. the Hawkeyes. Horvath might be a week or 2 away, but perhaps longer.

Point being, Purdue doesn’t have the depth to absorb injuries on a week-in and week-out basis, and having top-flight players missing from the offense has obviously hurt the offense’s ability to score. Remedying that issue might come when they get out of the training room and back onto the field.

Let it loose 

In 2020, Brohm was criticized by many, including himself, for playing too conservatively on offense.

Is he doing it again in 2021?

Purdue must find a way to put points on the board, and a freewheeling open-the-playbook approach seems like the only way possible. It might come with mistakes, but playing closer to the vest isn’t working either, as evidenced by 3 straight games of 13 points.

It’s Wisconsin

The game that matters for the Boilermakers might not be the next one, a trip to the second-ranked Hawkeyes in Iowa City, but the one after.

The Wisconsin game will be as close to must-win as possible, considering the Boilermakers need 3 victories to get to 6 and an offensively-challenge Badgers’ squad will represent a good opportunity. But man, Purdue’s recent history vs. Wisconsin has been bad, without a win in the series since 2003. And Purdue hasn’t beaten Wisconsin in Ross-Ade Stadium since 1997.

But this isn’t a typical Wisconsin team either, with it struggling so badly on offense. Maybe this is Purdue’s year. It’ll almost have to be.

The offense. Really?

It’s just so bizarre that a Brohm-led offense is without an identity, but that’s where Purdue stands right now.

The Boilermakers can’t settle on much of anything, unless erratic play counts. But the Boilermakers need to turn to a wide-open free-wheeling style if they are to get anything accomplished in the last 7 games of the season.

Last dance

Purdue has 7 games remaining this season.

Could they also be the last 7 games for Bell and defensive end George Karlaftis, both of whom will be high draft picks in the NFL?

Whether that’s this season or next remains to be seen. But if Bell and Karlaftis are playing their last seasons, then Purdue would love to see them end in a warm-weather bowl game. For that to happen, Purdue is going to have to get on a roll.