The Purdue defense was hit or miss throughout the Jeff Brohm era. There were good games and bad games which led to good seasons and bad seasons. Ryan Walters has a track record of putting together good defenses as a coordinator and brings together a group of coaches that he’s worked with previously to accomplish the same thing as head coach.
Leaning into Purdue’s history of flight, campus airport, and the offense being a variant of the Air Raid, the defense has been named the Air Strike.
What is the Air Strike?
Ryan Walters runs a base defense consisting of 3 big linemen, 2 outside linebackers that set up on the line of scrimmage, 2 inside linebackers, and 4 secondary players. There are some variations off of this - I don’t think it will be uncommon for a nickel back to replace one of the inside linebackers - but that’s the basics of the formation.
By having five players set up on the line of scrimmage, the defense is designed to limit the opposing side’s run game in addition to confusing Scott Frost. The three defensive linemen (all three starters should be over 300 pounds) should plug the gaps and prevent big holes from opening up front. The two outside linebackers attempt to contain the run and push things back inside to the waiting inside linebacker or get to the quarterback on passing plays. Inside linebackers need to clean up the run attack and be able to cover tight ends or running backs out in the passing game.
In the secondary, the defensive backs are taught to be very aggressive. They will get more than their share of defensive pass interference calls, but should offset that with more incompletions and interceptions. Walters wants you to pass the ball. Then he wants his defense to take advantage of errant throws.
There are some weaknesses to Walters defense. It is susceptible to cutbacks in the run game and requires the inside linebackers to clean those up. If the opposing offense has a big, physical tight end it can also struggle to cover them (as demonstrated by Purdue’s Payne Durham last season).
The defense worked well for the Illini the last two seasons, helping propel them back into respectability once again. The Illini gave up just 3.3 yards/carry and less than 100 yards on the ground (against a schedule filled with run first teams in the Big Ten West). They combined this with 24 interceptions and held opponents to just 273.5 total yards/game and only 12.8 points/game.
Now this success wasn’t all due to Walters scheme. Although he brought with him the outside linebackers coach and two defensive analysts, the Illini defensive line coach and secondary coach have remained in Champaign. We also should not forget that the Illini sent three secondary players to the first three rounds of the NFL draft.
For those concerned that Purdue won’t be able to repeat what the Illini did last year, there are a few reasons to be optimistic: 1) Purdue brought in a defensive line coach that Walters has worked with before at Missouri where they had plenty of success. 2) Walters is a former secondary coach himself and likely had something to do with the developmental of those players. 3) The staff hit the transfer portal hard to find players that can implement their vision of the defense.
Speaking of the players, let’s look at the personnel for this season. I won’t be breaking the defense into neatly defined starters and backups like the offense due to the greater uncertainty on who starts and who doesn’t. There will probably be more of a rotation on the defensive side of the ball anyway.
The nose tackle spot should primarily be a rotation of Cole Brevard and Damarjhe Lewis. Brevard is a big bodied tackle and former Penn State player that performed well in the rotation for Purdue last year. He should be backed up by Damarjhe Lewis assuming Lewis is fully recovered from the lower leg injury that caused him to miss the entire 2022 season. Lewis is slightly smaller than Brevard but between the two of them they should hold down most of the snaps at the position nicely.
Behind Brevard and Lewis is Mo Omonode who probably should have redshirted last season but was forced into action when Lewis went down in fall camp. I suppose Omonode could use that redshirt this year, but I suspect he takes the remaining snaps that Brevard and Lewis don’t account for. After Omonode is J.P. Deeter, who is coming off a redshirt, and true freshman Jamarrion Harkless. Expect Harkless to redshirt. At 6’3”, 315 pounds, he’s probably closer to physically ready that most freshman nose tackles, but there are enough options in front of him that it makes more sense to redshirt him.
Purdue will play two defensive ends and wants them to be the size of your typical defensive tackle. By moving from a 4-3 to a 3-4, the defensive ends on the roster didn’t necessarily fit that prototype. As a result, Walters brought in three defensive linemen who should be a big part of the rotation. Malik Langham, Jeffrey M’Ba, and Isaiah Nichols all fit that mold and all three come to West Lafayette from the SEC. They won’t completely replace the returning players, but they are the favorites to start.
Returning defensive ends Joe Anderson, Prince Boyd Jr., and Sulaiman Kpaka are slightly smaller than the three newcomers and perhaps slightly less suited to the run stopper role. They should still be part of the rotation and I think Anderson in particular could see more time on obvious passing downs or against pass heavy offenses.
Joe Strickland, Drake Carlson, and walk-on Jayden Scruggs finish out the defensive line room. All three are freshmen, with Strickland and Scruggs coming off their redshirt season. All three need to add strength and weight to move up into the rotation with the depth in front of them.
Yanni Karlaftis is also listed as a defensive lineman on the official Purdue roster. However at just 235 pounds, he would seem to be almost completely limited to 3rd and long plays where he could get after the QB from the edge. There have been statements that indicate Yanni will instead be playing linebacker this season. With his size and the lack of depth at the inside linebacker position, I’m expecting him to be an ILB this season despite what the roster says.
The outside linebacker room is fairly deep for Purdue this season. Kydran Jenkins returns after breaking out late last season as an edge rusher for the Boilermakers and is expected to take one of the two starting spots. The battle to join him in the starting lineup is thought to be between Nic Scourton (formerly Caraway) whom has been talked up all spring and summer and Khordae Sydnor who played significantly more than Scourton last season.
Behind Scourton and Syndor, sixth year Scott Humpich and sophomore Roman Pitre offer decent depth. We will see how both adjust to lining up on the line of scrimmage as opposed to off the line.
Two freshman complete the outside linebacker room in Will Heldt and Mondrell Dean. Heldt did enroll early, but I’m not sure I see either playing more than spot minutes and the goal should probably be to preserve their redshirts if possible. In a pinch, a couple of the smaller defensive ends (Joe Strickland, Joe Anderson, Sulaiman Kpaka may be better options as emergency OLBs this season after being edge rushers under Brohm.
The inside linebacker room is thin for Purdue this upcoming season. But Walters and co. did not appear to heavily pursue any in the transfer portal and certainly didn’t bring any transfers in. That may indicate they would rather play 5 defensive backs instead. Their 2024 recruiting class would seem to indicate the same based on the quantity of verbal secondary commits. Most Purdue football coverage still seems to be operating under the assumption that Purdue will utilize two inside linebackers though, so we will assume the same until shown otherwise.
Those starting inside linebackers will be OC Brothers and either Clyde Washington or Yanni Karlaftis. Brothers was a starter in 10 games last season, finishing fifth on the team in tackles. The former Auburn player has been a decent part of the rotation the past two seasons. Washington is a senior that appeared in nine games last year, making just one start. He has not put up big numbers, but by virtue of being one of the few returning inside linebackers may win the spot. Yanni is of course the younger brother of George Karlaftis and a former 4 star recruit in his own right. He has played sparingly his first two seasons, as he was viewed as a tweener between defensive end and linebacker. The new staff appears to have the same issue but there is playing time available at the inside linebacker spot and as mentioned above Karlaftis spent spring ball playing there.
Behind those three sits redshirt freshman Domanick Moon as well as true freshmen Owen Davis and walk-ons Farrell Henderson III, Hudson Miller, and Joey Sumlin. I wouldn’t be shocked to see Scott Humpich move to inside linebacker midseason if injury concerns raise their head either.
The secondary saw a ton of turnover this offseason. That’s not totally surprising since Walters is a former secondary coach, and the reinforcements should be a welcome sight after the Boilermakers secondary was shredded by opposing teams last season.
Incoming cornerbacks Marquis Wilson, Salim Turner-Muhammad, and Markevious Brown should compete with Jamari Brown for the starting corner spots and be the primary rotation players. All three were big pickups and could be immediate difference makers. Jamari Brown is the only returning cornerback who played last year. He’s struggled somewhat with technique the past few years, but has the length and speed that he could excel with some teaching by the new staff.
Behind those four, sit Botros Alisandro, Braxton Myers, and Jaxon Mull. Alisandro has more experience than the other two and comes to Purdue from the JUCO ranks. Myers and Mull are younger but have plenty of long term potential. Don’t be surprised if Myers breaks into the rotation this season.
Freshman Zion Gunn and Derrick Rogers Jr. are both likely redshirts.
At the safety position, Purdue returns their top three guys from last season. Although the trio struggled somewhat (the whole secondary struggled), they are experienced and have all had moments of success. Cam Allen and Sanoussi Kane are the likely starters. Antonio Stevens should also be in the rotation.
Anthony Brown (a redshirt freshman transfer from Arkansas) is seen by some as the favorite for the final spot on the two-deeps, but he will have to hold off returning redshirt freshman Joseph Jefferson II as well as early enrollee Dillon Thieneman. Thieneman is the latest member of the Thieneman family to play for Purdue. Early reports have him impressing the coaching staff and a video clip from practice appeared to show him playing with the 1s (although perhaps I’m reading too much into one clip).
Other freshman safeties are Ethon Cole and Winston Berglund. I could see either making appearances on special teams this season.
Despite winning the Big Ten West last season, the defense didn’t cover itself in accolades. A new scheme, competent coaching staff, and a bunch of new pieces have the potential to change that, but it’s also possible that it takes time for them to gel. For a Purdue team that needs early wins in the non-conference to secure bowl eligibility, that growing process may not have the time needed to develop.
The run defensive scheme puts a lot of stress on a thin inside linebacker group. I’m also concerned about the viability of a defense so heavily focused on pass defense in the Big Ten West where (with no due respect to the Badgers planned Dairy Raid) there aren’t any pass first teams. That defensive scheme worked for Illinois last season, but does Purdue have the pieces to replicate that this year?
I’m hoping for incremental improvements from last season and improvements from game to game.