Buffalo brings back a familiar face to lead their defense under new head coach Joe Brady.
The Buffalo Bills made a significant addition to their coaching staff by hiring Jim Leonhard as their new defensive coordinator. The move reunites the franchise with a player who began his NFL journey in Buffalo nearly two decades ago.
Leonhard brings impressive credentials from both college and professional coaching ranks. His appointment marks another step in the Bills’ transformation under first-year head coach Joe Brady.
Let’s take a closer look.
Leonhard’s Journey from Undrafted Rookie to Coordinator
The Wisconsin native carved out a successful playing career against all odds.
Leonhard joined Buffalo as an undrafted free agent safety in 2005 after his college career at Wisconsin. Despite his size disadvantage, he played 10 seasons in the NFL, appearing in 142 games with multiple teams, including the Ravens, Jets, and Broncos.
His playing intelligence and work ethic became his trademarks throughout his career. He recorded 431 tackles and 14 interceptions before retiring in 2014, proving doubters wrong at every turn.
College Coaching Success Built His Reputation
Wisconsin became the proving ground for Leonhard’s defensive mind.
After retirement, Leonhard returned to Wisconsin as a defensive backs coach in 2016, before being promoted to defensive coordinator. His defenses ranked among the nation’s elite, finishing in the top five for total defense four times during his tenure.
The Badgers consistently dominated opponents under his leadership from 2017 through 2022. He even served as interim head coach in 2022, showcasing his ability to lead an entire program during transition.
Denver Provided NFL Coaching Experience
The Broncos gave Leonhard his first taste of professional coaching.
Leonhard joined Denver in 2024 as defensive backs coach and pass game coordinator under Sean Payton. He earned a promotion to assistant head coach in 2025 while maintaining his coordinator responsibilities for the secondary.
The Broncos’ defense flourished under Leonhard’s coaching of the defensive backfield and coordination of the pass game. Denver recorded 68 sacks in 2025, just four shy of tying the NFL single-season record set by the 1984 Chicago Bears.
Statistical Excellence In Denver
The numbers prove Leonhard’s impact on the Broncos’ defense.
Denver allowed the second-fewest yards per game at 278.2 during the 2025 season with Leonhard on staff. The defense also finished first in pass defense, while cornerback Patrick Surtain II won Defensive Player of the Year.
The Broncos ranked third in yards allowed per pass attempt over two seasons with Leonhard. Their third-down defense allowed just a 35.5 percent conversion rate, ranking fourth best in the league during that span.
Brady Builds His Coaching Staff
The new Bills head coach prioritized finding the right defensive leader.
Joe Brady became Buffalo’s head coach after being promoted from offensive coordinator in late January. The 36-year-old Brady emphasized hiring the best coaches available rather than simply choosing friends or familiar faces during his introductory press conference.
Brady previously worked with offensive coordinator Pete Carmichael in New Orleans, creating established relationships within his staff. Leonhard represents the second former Broncos assistant Brady hired, joining Carmichael, who also spent time in Denver before coming to Buffalo.
Buffalo Needed Defensive Changes
The Bills ranked inconsistently on defense during the 2025 season.
Buffalo allowed the 12th-fewest points per game at 21.5 during the 2025 campaign under former coordinator Bobby Babich. However, the run defense struggled mightily, ranking 28th by allowing 136.2 yards per game on the ground.
The defensive inconsistency contributed to another playoff disappointment for the Bills. Buffalo lost to Denver 33 to 30 in overtime during the divisional round, ending their season and ultimately costing Sean McDermott his job.
Competitive Hiring Process
Multiple teams sought Leonhard’s services this offseason.
Leonhard interviewed with the Los Angeles Chargers and Baltimore Ravens for their defensive coordinator openings. His name surfaced in connection with nearly every available coordinator position, reflecting his rising status among coaching candidates.
Buffalo ultimately won the competition for his services after Brady made his pitch. Leonhard chose the Bills over other suitors, returning to where his professional football journey first began two decades earlier.
Schematic Changes Expected
Leonhard may bring a new defensive philosophy to Buffalo.
The Bills operated a traditional four-down defensive front under McDermott for nine seasons. Leonhard coordinated three-down defenses at Wisconsin and helped coach that scheme in Denver, suggesting potential structural changes ahead.
Buffalo could transition to a base three-down alignment with an extra linebacker on the field. The shift would represent a significant philosophical change for a franchise that relied on McDermott’s four down principles since 2017.
Player Development Track Record
Leonhard has consistently elevated defensive backs throughout his coaching career.
Multiple defensive backs earned All-Pro honors under Leonhard’s coaching at various stops. At Wisconsin, he developed numerous players who went on to successful NFL careers through his technical teaching and scheme versatility.
Patrick Surtain II became a three-time All-Pro and won Defensive Player of the Year with Leonhard coaching Denver’s secondary. His ability to maximize talent gives Buffalo hope for improved performance from their own defensive backs moving forward.
TL;DR
- Jim Leonhard returns to Buffalo as defensive coordinator after starting his NFL career there as an undrafted rookie.
- He brings elite college credentials from Wisconsin where his defenses ranked top five nationally four times.
- Leonhard helped Denver’s defense record 68 sacks and allow the second-fewest yards per game in 2025.
- Buffalo hired him under new head coach Joe Brady to fix defensive issues, especially against the run.
- The Bills may switch from a four-down to three down defensive alignment under Leonhard’s leadership.
- His track record of developing All-Pro defensive backs gives Buffalo optimism for defensive improvement.
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This article was made with AI assistance and human editing.
