As Sean Payton continues his quest to become the first head coach in NFL history to win a Super Bowl with multiple franchises, his legacy -- and coaching tree -- continue to grow significantly.
It's been a busy offseason for many Denver Broncos assistant coaches, but perhaps none more so than defensive backs coach and pass game coordinator Jim Leonhard, who has gone on an interview circuit for the ages. Leonhard took job interviews with just about every team that had a need for a defensive coordinator, but ended up taking a job with the Buffalo Bills.
Leonhard has been one of the more coveted assistants in the NFL the past couple of years, and his patience paid off with a heck of a job in Buffalo, where he'll be tasked with rehabilitating a Buffalo defense that was a massive disappointment in 2025.
Broncos lose Jim Leonhard as Buffalo Bills make him their new defensive coordinator
The #Broncos’ offseason of staff turnover continues.
— Luca Evans (@bylucaevans) January 31, 2026
The Bills are hiring Denver defensive passing-game coordinator Jim Leonhard as their defensive coordinator, a source confirmed (@RapSheet first). Leonhard was promoted to Denver’s assistant HC this past year.
This was somewhat of an expected loss for the Broncos this offseason, as the more time has dragged along, the more it's felt like defensive coordinator Vance Joseph will be returning. There are still two head coaching jobs available -- Raiders and Cardinals -- but the rumor mill is saying the Raiders are more likely to hire Klint Kubiak and the Cardinals?
Well, nobody really knows what's going on there, but Ron Rivera might be a front-runner for the job.
With the likelihood that Joseph is returning, Leonhard's chance of potentially being his successor as the defensive play-caller in Denver are diminishing. It's not a bad idea, on his part, to take an attractive job like the one in Buffalo, where Joe Brady was just recently named the team's newest head coach.
And in fact, this isn't even the first poaching job the Bills have done from Denver's staff. It won't likely be the last, either. They brought in veteran coach Pete Carmichael as their offensive coordinator, plucking him off of Sean Payton's staff in Denver before making Leonhard their defensive coordinator.
Leonhard is highly respected around the league and although he's not a first-time defensive play-caller, he'll be a first-time defensive play-caller in the NFL. He was the defensive coordinator at Wisconsin from 2017-2022, and NFL teams loved the way he brought along the defensive backs in his time with the Badgers.
The Broncos have had Leonhard on their staff since 2024, so it wasn't like he was around for a long time, but this is a role he was being groomed for since he was brought on.
As a player, Leonhard was signed as an undrafted free agent by the Bills in 2005, and had a second stint with the team as recently as 2013. This was a homecoming opportunity he couldn't pass up.