Jim Leonhard may be a first-time defensive coordinator in the NFL, but his experience calling the defense in college speaks for itself.
In his six seasons as defensive coordinator of the Wisconsin Badgers, Leonhard’s defenses wreaked havoc on the opposition. His defenses finished in the top 10 in total defense in five of his six seasons. He had the top unit in total defense twice over that span of time.
Between his defense dominating at Wisconsin and a few seasons learning under Vance Joseph in Denver, Leonhard seems ready to take over a Buffalo Bills unit that has underperformed in the biggest of games.
Buffalo has some pieces that seem like good fits for Leonhard’s defense, but coaches generally sign a few players that they have coached in the past to help in the transition.
Here are a few free agents to keep an eye on as free agency approaches.
Chiefs LB Leo Chenal
Chenal was one of Leonhard’s stars at Wisconsin. In 2021, Chenal emerged as one of the nation’s top linebackers. He recorded eight sacks, 17.5 tackles for loss, while finishing the year with 114 tackles and forced two fumbles in 11 starts under Leonhard.
In Kansas City, Chenal has emerged as a blitzer and situational run-stuffer, while also improving in coverage. A reunion with Leonhard would give Chenal a larger role in Buffalo, and no one knows how to unleash the athletic player more than the Bills’ new defensive coordinator.
Cowboys LB Jack Sanborn
Sanborn was another one of Leonhard’s standout players with the Badgers. In his final season at Wisconsin, Sanborn recorded 91 total tackles (16 tackles for loss) and five sacks.
Sanborn spent the first three seasons of his career with the Chicago Bears before signing a one-year deal with the Cowboys last year in free agency. The linebacker is coming off a down year in which he appeared in just six games and recorded 34 total tackles (1 tackle for loss).
Sanborn makes sense as a low-end signing in free agency.
Broncos LB Alex Singleton
As you can see, the Bills will have plenty of linebacker options with ties to Leonhard.
Singleton’s name may sound familiar to Bills fans as he is the linebacker who forced James Cook to fumble the ball early in Buffalo’s divisional round loss to the Broncos. Simply put, Singleton is a tackling machine. In five of the past six seasons, Singleton has recorded 120 tackles or more. The linebacker has recorded 25 tackles for loss, 22 quarterback hits and five sacks over that same span of time.
Singleton’s journey is one Bills fans can get behind. After his collegiate career at Montana State, Singleton spent multiple seasons on offseason or practice squad rosters. Eventually, the linebacker decided to make the jump to the CFL. He played three seasons with the Calgary Stampeders and earned plenty of accolades during his time in Canada. He was a two-time CFL All-Star and named the league’s most outstanding defensive player in 2017. He also won the Grey Cup in 2018 before making his return to the NFL.
Broncos S P.J. Locke
P.J. Locke is another name to keep in mind for Buffalo’s defense, but getting him to leave Denver could be difficult.
Locke is on record telling the Denver Gazette would like to retire as a member of the Broncos.
“I obviously want to be back here,’’ said Locke. “I would love to retire here. But I just got to see how it goes.”
Opportunity could be Buffalo’s biggest selling point. Locke was a backup for the Broncos in 2025 behind Talanoa Hufanga and Brandon Jones. After Jones went down with an injury for the year in mid-December, Locke returned to the lineup and played well. He recorded an interception and forced a fumble in Denver’s divisional round win over Buffalo.
Leonhard could potentially sell the soon-to-be 29-year-old safety on a starting opportunity in Buffalo opposite Cole Bishop.
Broncos DL John Franklin-Myers
John Franklin-Myers is no stranger to the Bills after his time with the New York Jets. Franklin-Myers was acquired by Denver via trade during the 2024 NFL Draft and thrived with the Broncos.
In his two seasons with the Broncos, Franklin-Myers has recorded 14.5 sacks along with 33 quarterback hits and 14 tackles for loss. Buffalo needs some reinforcements on the defensive line and Franklin-Myers makes plenty of sense.
