Why Aaron Glenn could—and should—be the Detroit Lions next defensive coordinator

Ever since the news of Dan Campbell—reportedly—becoming the next head coach of the Detroit Lions broke, many have questioned the decision from a variety of angles.

A tight ends coach with little head coaching experience? What happened to getting the next hot coordinator like Robert Saleh, or a veteran head coach like Marvin Lewis?

What’s the deal with his philosophy on offense I read about on Twitter? Quarterbacks take the backseat as the team establishes the run? I’ve seen this movie before.

Isn’t this too big of an overcorrection from the Matt Patricia era? Sure, Campbell seems like a great character hire, but what does he know about X’s and O’s?

And you know what? They’re all worthwhile reservations and questions to be had about the newest head coach of the Lions. Campbell won’t have the chance to put any of these to bed until his Lions hit the field in 2021, but there is one pervasive question out there he can put to rest relatively soon: For a guy with such little coaching experience, what kind of staff can he put together?

Another great question to have, but the answer shouldn’t be too difficult for Campbell to figure out. Look no further than the team Campbell is departing from to find the Lions' next defensive coordinator: New Orleans Saints defensive backs coach Aaron Glenn.

Glenn is the former cornerback who played 15 seasons from 1994 to 2008, earning Pro Bowl accolades in three of those seasons and racking up an impressive 41 interceptions during his NFL career.

But all of those accomplishments, of course, don’t mean much when it comes to being a successful coach in the NFL. The drive to learn and adapt continuously are hallmarks of some of the best coaches in the league, and to that end, Glenn is a student of the game.

Dan Pompei of The Athletic chronicled that and much more in a piece he published in December of 2020:

Glenn wants to know everything he can about the game. He sits in on the Saints’ special teams meetings just to learn. Glenn frequently questions college coaches such as Florida Atlantic defensive coordinator Jim Leavitt about the game’s progression at that level. During his downtime, he researches trends. Last offseason, he looked at why passing yards and points were increasing. He recently did a study on how Belichick’s defensive philosophy was evolving.

It’s easy from a cursory standpoint to write off Glenn’s interview with the New York Jets for their head coaching vacancy on January 11, 2021 as one of comfortability and familiarity since Glenn played eight seasons for the Jets—and has no experience even as a defensive coordinator—but that’s ignoring the impressive résumé Glenn has put together thus far.

Once he stepped away from his playing days, Glenn cut his teeth with the Jets as a pro scout in 2012 and then a college area scout in 2013 at the request of his former head coach and mentor Bill Parcells. Pompei’s piece paints an incredible picture of the genesis of Glenn’s coaching journey.

A member of the Jets’ four-decade team, Glenn was franchise royalty working an entry-level position. Superiors tried to defer to Glenn and show him the respect he had earned as a player. But he would not allow it. [Mike] Tannenbaum would ask another scout to run a menial errand, like filling the coffee pot or making copies. Glenn would say, ‘No, I got this.’

‘I wanted everybody in the room to know, even the other scouts, that I wasn’t too big to do the small stuff,’ Glenn says. ‘I wanted to start at the very bottom and learn every little thing there is about scouting.’

After humbling himself and learning the intricacies of scouting, Glenn’s coaching career started with the Cleveland Browns as the team’s assistant secondary coach for the 2014 and 2015 seasons. Glenn earned a promotion in 2016 when he became the defensive backs coach for the Saints and New Orleans’ secondary has been better for it.

In the 2020 season, the Saints’ pass defense ranked fifth in yards allowed per game (217.0), sixth in yards allowed per pass play (6.7), fourth in interception rate (3.23%), and maybe most impressively, second in the NFL in completion percentage allowed (59.8%). As a unit, the Saints ranked third in pass defense DVOA in 2020 (-14.7%) and you’re beginning to understand the imprint Glenn has had on the Saints’ secondary.

The dots are easy to connect between Campbell and Glenn. Both took the next step in their coaching career when they joined New Orleans in 2016, both are products of Texas A&M, and both have played under—and have an immense amount of respect—for Parcells.

The questions and reservations will remain until Campbell’s team takes the field in 2021, but having a coach like Glenn leading his defense will go a long way towards Detroit turning its fortunes around sooner than later.