Bills' Assistant Coaching Hires Signal Major Defensive Changes under Jim Leonhard

The Buffalo Bills are overhauling their defense in more ways than one.

After replacing defensive-oriented head coach Sean McDermott with offensive coordinator Joe Brady, the Bills brought in former safety Jim Leonhard as the team's new defensive architect.

While the 43-year-old Leonhard's arrival brings instant energy and excitement, his system represents a shift in philosophy of sorts.

"There's going to be change," said Leonhard. "It's been a system that they've played in for a long time. Just the structure of what they've done, and how they've done it, and why they have done it, it's going to be a change for them."

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While the Bills played primarily with either two linebackers and a nickel cornerback out of a three-linebacker base formation during the McDermott era, Leonhard has a history of employing an iteration of the 3-4 defense. Using only three down linemen, Buffalo will presumably feature four linebackers in its base defense under Leonhard's direction.

Assistant coaching hires hold clues

While safeties coach Joe Danna, who is one of the few assistant coaches being retained, expands his role to include the entire secondary, the Bills are not filling the nickel coaching position that McDermott established.

Former Bills' nickel coach Mike Pellegrino is reportedly joining the Philadelphia Eagles' organization as it appears that Buffalo may no longer regularly deploy a nickel cornerback.

Meanwhile, the Bills, who had one linebackers coach (Al Holcomb) under McDermott, have hired an inside linebackers coach (John Egorugwu) and an outside linebackers coach (Bobby April III) to fit the 3-4 defensive scheme.

Bills safeties coach Joe Danna talks with the team's new safety Kareem Jackson at St. John Fisher University in Pittsford, Thursday, Aug. 1, 2024. | Shawn Dowd/Rochester Democrat and Chronicle / USA TODAY NETWORK

Taron Johnson's future

With the change in defensive formation, it's natural for one to question nickel cornerback Taron Johnson's future in a Bills' uniform.

Johnson, a 2018 fourth-round draft pick, established himself as an important piece on McDermott's defense for the last eight seasons. He's played 113 career regular season games for the Bills, earning an All-Pro nod in 2023.

While Johnson's production dipped in 2025 as he dealt with a couple nagging injuries, he's under contract for the next two seasons, and it doesn't make financial sense to dump him this offseason.

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According to Spotrac, releasing or trading Johnson would create less than $2 million in salary cap space while slapping Buffalo with a $9.5 million dead hit. It seems as if a restructure is the way to go, and, although he may not have a traditional position in Leonhard's defense, Johnson can likely find a way to make himself useful in some way.

Detroit Lions place kicker Jake Bates (39) tries to recover an onsite kick against Buffalo Bills cornerback Taron Johnson (7) during the second half at Ford Field in Detroit on Sunday, Dec. 15, 2024. | Junfu Han / USA TODAY NETWORK via Imagn Images

"We're excited, as a coaching staff, to really be able to create something that is best for their skill sets and fits their personalities," said Leonhard, who emphasized adaptability in coaching.