After 3 consecutive losing seasons in West Lafayette, Purdue needs a bounce-back in 2021.

And the pursuit of that starts with the beginning of spring practice Friday, then culminates with the last of three scrimmages on March 19.

Clearly, Purdue has a boatload of questions following a 2-4 season, as Jeff Brohm enters his fifth year. Here are the 8 most important:

What’s the biggest question on defense?

Well, a better question would be: What’s not in question on defense? Purdue has a new defensive coordinator in Brad Lambert, who came over from Marshall after not getting the Herd head coaching job and is charged with trying to mold the Boilermakers back into the more competent group that Brohm had in his first couple seasons. And Lambert has two new assistants, too, in veterans Mark Hagen (in his second stint in West Lafayette) and Ron English.

So, the biggest question is this: Will Lambert better fit Purdue’s existing personnel — the strengths being on the defensive line, particularly George Karlaftis, Anthony Watts and DeMarcus Mitchell — into a scheme that makes sense. In his short 6-game stay last season, Bob Diaco tried to jam in a scheme that didn’t fit Purdue, and we know how well that worked out.

Will Purdue decide on a quarterback?

Probably not. Former walk-on Aidan O’Connell won the job in training camp last season, won his first 2 games, then broke his foot, sidelining him for the rest of the season. Jack Plummer took over, and was statistically slightly better, but also finished the year 0-3.

We know the differences by now: O’Connell has a great arm, able to drive the ball down the field (which Brohm values), but he’s a pocket passer. Plummer can get out of the pocket and ad-lib to make plays (which Brohm values), but probably doesn’t quite have the same arm.

But, whatever. The back-and-forth has become nauseating. It’s not yet clear whether O’Connell will be full-go for the spring following his foot surgery. If not, then Plummer will get a majority of the No. 1 snaps. Maybe that gives the junior a chance to solidly grab hold of the job.

More than likely, however, this battle goes into the fall.

How does the offensive line shake out?

This sounds a bit odd to say, but the O-line might be the Boilermakers’ best and deepest unit.

Even a year ago, saying such a thing would have drawn strange looks. But credit to Purdue’s recruiting and line coach Dale Williams, who has developed enough of those former recruits into a group that can go as many as 8 deep. Figuring out which of the 8 capable players form the best starting unit is a good problem to have.

It’s likely that Cam Craig, who missed most of last season with a knee injury, will slide over to left tackle (longtime starter Grant Hermanns is on to the NFL) once the sophomore is healthy enough to play. Newcomer Tyler Witt, a grad transfer from Western Kentucky, could jump into Craig’s former spot at left guard. Center will be a battle between incumbent Sam Garvin and Gus Hartwig, who started at guard as a true freshman in 2020. Kyle Jornigan and Spencer Holstege will compete at right guard, and perhaps D.J. Washington too, while Greg Long, a former J.C. transfer who decided to stick around for a 6th year. Eric Miller is a valuable and experienced swing tackle.

How does Purdue replace Rondale Moore?

It doesn’t. But at least Purdue has options in the slot, and one of them proven. Jackson Anthrop, who led Purdue in receptions in 2017, decided to return for one more season after having an injury-plagued 2020. He’s not the game-breaker that Moore is — few people are — but Anthrop is as reliable and hard-working as one could ask for. As a No. 3 option, behind David Bell and Milton Wright, he could be very dependable, especially on short-yardage 3rd downs.

But watch for T.J. Sheffield too. The sophomore was primarily a special-teamer last season, but he has a bit more shiftiness than other options, if he can grasp the intricacies of Brohm’s offense.

Who is an off-the-radar player to watch?

Sanoussi Kane.

Purdue is unsettled in its defensive backfield, with only cornerback Cory Trice and safety Cam Allen seemingly solidified as starters. But the Boilermakers having openings at the other two starting spots and at nickel back.

Marvin Grant, who has shown a knack as a big-hitter during his limited opportunities, might get the first crack at safety, and Dedrick Mackey has significant starting experience at cornerback. But Kane. A 6-foot, 200-pounder sophomore, could compete for time, or fill the spot at nickel. He’ll get a lot of opportunities over the next month.

Will 2021 be the year of the Karlaftis Brothers?

It’s very possible. Purdue needs older brother George to get healthy because that might be the only thing holding him back. Last year was a mess, from a severely injured ankle that limited the first half of his season to COVID putting him on the sideline for the second. The defensive end still led Purdue in sacks, with 2, despite playing only about a game-and-a-half completely healthy. He’ll be eager for a huge season — and will undoubtedly work toward it — to see if that leads to an early chance at the NFL.

Yanni Karlaftis is on campus early, not that he has to travel very far from his West Lafayette home. But the highly-regarded rookie will get every single opportunity to win a starting linebacker job from Day 1.

What does Purdue do about its running game?

Get better, it would hope.

The Boilermakers finished last in the league in rushing in 2020, averaging only about 81.5 yards per game. Starting running back Zander Horvath, a big 6-3, 230-pounder, was solid, with a team-high 442 yards. But he needs a sidekick (or he needs to be the sidekick). Former starter King Doerue started last year hurt, then never really got into a groove, and had only 64 rushing yards. Can he return to form? And if he can’t, then who grabs hold of the second spot?

Ideally, Purdue finds a speed back to pair with its bruiser Horvath.

Why should I be optimistic?

Because it’s the spring.

But also because Purdue has several A+ players: David Bell, George Karlaftis, DeMarcus Mitchell, Cam Craig, Milton Wright, Gus Hartwig, and several good ones on the second tier, too. If those players find a high level and can stay healthy, they could lead the Boilermakers to a big season in 2021.