Author Explains Jim Leonhard's Coaching Acumen Was Obvious 15 Years before Bills' Job

Buffalo's newest defensive coach has had a quick rise to becoming an NFL team's top coordinator, but it's no surprise to at least one particular acquaintance of the former player.

Buffalo Bills' first-year defensive coordinator Jim Leonhard (center) watches as his defense takes the field during first-half action of the Bills' preseason game against the Pittsburgh Steelers at the new Highmark Stadium on Aug. 27, 2026, in Orchard Park, New York. | USA TODAY Network via Reuters Connect

The Buffalo Bills have made many sweeping changes since the firing of longtime head coach Sean McDermott back in January.

While former offensive coordinator Joe Brady is still a familiar face—just now in a different role as the Bills’ head coach—there aren’t too many other people around the building who have been with Buffalo in recent seasons of the past.

But, that’s what owner Terry Pegula presumably wanted when he dropped the hammer down on McDermott.

Most notably, Pegula wanted to see a change on the defensive side, as he felt that franchise quarterback Josh Allen and the offense had been handcuffed too many times before by the other side of the ball, particularly in the most critical moments of the postseason.

With McDermott out, a new coordinator and philosophy have arrived

Sep. 15, 2013; Orchard Park, NY, USA; Former Buffalo Bills' defensive back Jim Leonhard (35) awaits a play to unfold in front of him during a past NFL game between the Bills and the Carolina Panthers at Ralph Wilson Stadium. | IMAGN IMAGES via Reuters Connect

So, along came the hiring of new defensive coordinator and former Bills’ safety Jim Leonhard, who played for the Western New York (2005-2007, 2013) franchise on two separate occasions during his 10-year NFL career before ultimately making his way back this winter after Brady officially brought him on board at the very end of January.

“I feel like I’m in a good place—as good as I can (be)— but, I have nothing to really judge it on, right?” Bills’ head coach Joe Brady said to reporters early on in his tenure back during veteran minicamp in June. 

“So, (I’ve tried to) surround myself with good people, good players, and the rest will take care of itself.”

And, although it might be Leonhard’s first coordinator job in the National Football League, it’s certainly not his first go-around as a defensive “teacher” or leader.

Nov. 19, 2022; Lincoln, Nebraska, USA; Former University of Wisconsin Badgers' interim head coach Jim Leonhard reacts to a play during the fourth quarter of a collegiate football game between the Badgers and the Nebraska Cornhuskers at Memorial Stadium. | USA TODAY Sports

A defensive backs coach, defensive coordinator, and an interim head coach during his time at the University of Wisconsin—his alma mater—from 2016 to 2022 with head coach Paul Chryst, the former undrafted Badgers’ safety was also recently a senior football analyst at the University of Illinois (2023) under head coach Bret Bielema, as well as the defensive backs coach (2024) and assistant head coach/defensive passing game coordinator (2025) for the Denver Broncos under longtime NFL head coach Sean Payton and Denver’s defensive coordinator, Vance Joseph, just last season.

And, the one-time professional safety has seemingly taken at least a little something that he’s learned from each of those stops and used it to help formulate his plan for the upcoming season that he and his defense—the youngest starting unit in the league—are about to embark on during the 2026-2027 NFL campaign under Joe Brady, who is also the youngest lead man in the league at just 36 years old.

Leonhard, meanwhile, will turn just 44 years old later this fall on October 27.

Leonhard using lessons learned from previous stops

Buffalo Bills' new head coach Joe Brady (left) talks with new Bills' defensive coordinator Jim Leonhard (right) during the opening day of Buffalo's training camp at St. John Fisher University in Pittsford, New York, on Wednesday, July 29, 2026. | USA TODAY Network via Reuters Connect

“It’s been a lot of fun to be back. You know, obviously (there are) a lot of familiar faces, but a lot of change, as well. So, to get back into Buffalo (has been great),” Buffalo’s new defensive coordinator Jim Leonhard said during an appearance on the Centered on Buffalo Podcast with former longtime Bills’ center Eric Wood prior to training camp.

Wood, although on the opposite side of the ball, was one of Leonhard’s teammates on the Bills in 2013.

“(We’re) trying to take a lot of stuff in as far as the questions (and) the reactions. I love to read a room, right? Just go sit in some of those rooms, and just (see) how the guys are taking the coaching and where they kind of start turning their head to the side and feel confused. 

And then, at the end of the day, we’ve got to create what’s best for them. . . . It’s my job—I feel like—to expose them to a lot of, you know, what I see as the vision: what could it be, right? Then, let’s fit these pieces where they need to be.”

Now, training camp and the preseason are behind all 32 NFL franchises.

And, Leonhard’s first year as a professional coordinator—no matter how much experience he has elsewhere—will be a challenge for a multitude of reasons: no doubt. 

Especially considering the Bills will face opponents such as the Houston Texans, Detroit Lions, Los Angeles Chargers, New England Patriots, and Los Angeles Rams—all playoff teams from the past few years—during the first five games of the upcoming regular season, which starts with a rather unfavorable road matchup against the Texans in Week One down in a hostile environment at Reliant Stadium in the Lone Star State this Sunday at 1:00 p.m. ET.

Leonhard displayed traits of future NFL coordinator dating back to playing days

Sep. 22, 2013; East Rutherford, NJ, USA; Former Buffalo Bills' defensive back Jim Leonhard (35) intercepts a pass in front of former New York Jets' wide receiver Santonio Holmes (10) during the first half of a past NFL game at MetLife Stadium. | IMAGN IMAGES via Reuters Connect

But, no matter how difficult it may seem to some outside observers, it’s a moment that Leonhard has been preparing for long before his coaching endeavors ever even began.

In addition to his time with Buffalo during his playing days, the one-time 5-foot-8, 188-pound safety also spent time with several other teams like the Broncos, Baltimore Ravens, New York Jets, and Cleveland Browns during this stint as a diminutive professional defender.

And, specifically, it was during his time with the Ravens (2008) and Jets (2009-2011) under former NFL defensive coordinator and head coach Rex Ryan—yes, that Rex Ryan, Bills Mafia—that Leonhard originally started showing signs of being a future defensive coach, at least in the mind of one particular person.

In a recent interview on The Ralph Rant podcast on YouTube on August 29, author Nicholas Dawidoff, who has been a finalist for the prestigious Pulitzer Prize, divulged some interesting information on Buffalo’s newest defensive coordinator.

When speaking about his critically acclaimed book, Collision Low Crossers: A Year Inside the Turbulent World of NFL Football, which depicted a year in the life of players and coaches on the 2011-2012 New York Jets, Dawidoff revealed that Leonhard was like another coach on the field—and the meeting room—for that Jets’ team.

Nov. 6, 2011; Orchard Park, NY, USA; Former Buffalo Bills' quarterback Ryan Fitzpatrick (14) quickly drops back to pass as former New York Jets' strong safety Jim Leonhard (36) rushes in from the edge while Bills' guard Andy Levitre (67) blocks during the second half of a past NFL game at Ralph Wilson Stadium. | IMAGN IMAGES via Reuters Connect

And, the safety had been doing so during his previous two seasons with New York, as well, which is when the franchise made back-to-back appearances in the AFC championship game for the first time since 1999.

The team has failed to reach a conference title game from that point on.

Was Leonhard the reason why? 

Well, maybe. Those Rex Ryan-led defenses were notorious for being complex. It’s part of the reason Ryan didn’t pan out as Buffalo’s head coach in 2015 and 2016.

But, be that as it may, Leonhard was somehow able to make it work from the back-end of the defense during his days in New York.

“(Jim Leonhard) has strong, resilient character, and yet he’s also really engaged and outward-looking at other people. And, he knew a lot about his teammates just in a very short amount of time. And, I think those are undervalued, but really, really important qualities (to have) in running a football team. 

Aug. 21, 2010; Charlotte, NC, USA; Former New York Jets' cornerback Kyle Wilson (20) and former Jets' safety Jim Leonhard (36) celebrate after Leonhard's interception during the Jets' 9-3 victory over the Carolina Panthers at Bank of America Stadium. | IMAGN IMAGES via Reuters Connect

“I mean, it’s a dangerous game, (and) it’s a game that requires a tremendous amount of commitment. There’s (a) 100% injury rate,” author Nicholas Dawidoff said of Leonhard in his interview on The Ralph Rant.

“So, working for someone who cares about you—and is interested in making your workday as pleasurable as possible—that’s a really good thing . . . Rex Ryan and Jim Leonhard are very different people, but they were really devoted to each other. That’s why, you know, Jim Leonhard came from Baltimore to the Jets, because Rex was so drawn to him as a football player, but also as a person. . . . It’s unsurprising to me—and I’m sure to anyone on that (Jets’) coaching staff—that he would be a successful coach after his playing career.”

Leonhard was ‘some sort of grad student’ during his time under Rex Ryan

Oct. 11, 2010; East Rutherford, NJ, USA; Former New York Jets' safety Jim Leonhard (36) pressures former Minnesota Vikings' Hall-of-Fame quarterback Brett Favre (4) during the first half of a past NFL game at the New Meadowlands Stadium. \ | IMAGN IMAGES via Reuters Connect

Apparently, the signs went even further than being personable and coachable as a young player, as well.

Leonhard took his preparation to levels not seen from other players on the Jets.

“He created this, like, 119-page document, which was his personal study of the Jets’ defense. And, he was so proud of this,” Dawidoff added.

“That was surprising to me because I thought, ‘Wow. Somebody’s creating this big document—which is a study of Rex Ryan’s defense—that sounds like he’s some sort of grad student. How does this go over on an NFL team?’ But, you know, people were pretty accepting. 

October 17, 2011; East Rutherford, NJ, USA; Former New York Jets' safety Jim Leonhard (36) lunges to tackle former Miami Dolphins' running back Daniel Thomas (33) during the first half of a past NFL game at the New Meadowlands Stadium. | IMAGN IMAGES via Reuters Connect

“Most (of) the football players didn’t seem like the stereotypical football players that, you know, people hear about in (movies), like, ‘Dazed and Confused’, or something like that. . . . You can’t play NFL football if you can’t study, so that already separates (people). 

“That creates a certain category of person right away.”

Now, 15 years removed from the days that Dawidoff spent with the former try-hard Jets’ safety in that locker room in New Jersey, Leonhard is about to—hopefully—instill his whimsical wisdom onto his defenders in Buffalo. 

Preseason proved fruitful for Bills’ new defense, but regular season will tell true story

Buffalo Bills' second-year defensive back Maxwell Hairston (31) gets ready to line up with teammates during first-half action of the Bills' preseason game against the Pittsburgh Steelers at the new Highmark Stadium on Aug. 27, 2026, in Orchard Park, New York. | USA TODAY Network via Reuters Connect

Only time will tell how it’ll go, but the preseason sure proved to be a sight for sore eyes amongst Bills Mafia on the defensive side of the ball as the Bills’ unit only allowed 209 yards per game and 3.7 yards per play en route to surrendering just 16 points per contest over the three-game stretch in August.

It’s time to take that body of work and put it into action against Houston quarterback C.J. Stroud and the Texans this weekend.

But, Leonhard is wired the right way for this upcoming opportunity, and—presumably—always has been.

“In a successful team, there’s going to be that familial quality. I mean, it’s just so dangerous, and it’s so exhausting—and it’s so time consuming—that the people who you’re going through this with, if, you know, you can feel happy for them—and enjoy being around them—it’s all (for) the better. . . . (That Jets’ staff) had great fluency with all kinds of people,” Dawidoff continued.

Buffalo Bills' first-year defensive coordinator Jim Leonhard (center) visits with his players during Day Two of Buffalo's training camp at St. John Fisher University in Pittsford, New York, on Thursday, July 30, 2026. | USA TODAY Network via Reuters Connect

“It’s a really intense, in-the-moment occupation, which goes on for a while and people are deeply engaged at something, and then the next year they just might be gone, or the next week they might be gone. So, (coaches and players) have this, sort of—to me, anyway—unusual ability to simultaneously be very, very much in the moment and very committed to one another, but also (possess) the ability to let go. 

“And, that’s just another personal quality I think is essential to make it in the NFL.”

With that said, sit back and watch the show on defense this season, Bills’ fans. It could be quite the display put on by Leonhard’s unit.

Sunday afternoon surely can’t come soon enough.