Jim Leonhard is overhauling the Bills defense and almost everyone on the roster is getting a shot with the first team in training camp. The Buffalo Bills will have a very different defense in 2026, and new defensive coordinator Jim Leonhard is seeing to that by giving a ton of players reps with the first-team unit. “The Bills are throwing everyone at the wall right now defensively and seeing what sticks. Article Continues BelowRookie safety Jalon Kilgore and second-year defensive lineman Landon Jackson—who bulked up to move from edge to interior defensive line this offseason—have also drawn rave reviews in Bills training camp. However, a majority of the players on the Bills' roster are still in the mold of that latter style.