Tuesday marks the beginning of a three-day mandatory minicamp for the Buffalo Bills. It will be their first under new head coach Joe Brady and while plenty of eyes will be on him, first-year defensive coordinator Jim Leonhard will draw even more attention.Leonhard is bringing in an entirely new scheme, and general manager Brandon Beane made several moves this offseason to build the defensive roster in his image. Early feedback from players who attended OTAs was positive, with Maxwell Hairston even saying they had more freedom under Leonhard.With expectations through the roof, there will be plenty of pressure on the coaching staff and players alike. Here's a look at which players will have the most to prove, and as is the case with Leonhard, there will be more eyes on defenders as they transition to his system.Keon Coleman, WRBuffalo Bills wide receiver Keon Coleman runs the ball during the fourth quarter against the Baltimore Ravens. | Mark Konezny-Imagn ImagesWith the addition of D.J. Moore and Skyler Bell this offseason, third-year wide receiver Keon Coleman is in danger of falling to the bottom of the depth chart. The 2024 second-round pick struggled with consistency this past season and despite Joe Brady saying a big leap is in store, it's hard to see how Coleman turns things around in Buffalo.The good news for him is that he will be given the chance to prove doubters wrong, but he can't afford any missteps. That means he has to be on top of his game, and has to go into minicamps with the understanding that he's fighting for his job.Javon Solomon, EDGE Buffalo Bills defensive end Javon Solomon reacts after recovering a fumble against the New England Patriots. | Brian Fluharty-Imagn ImagesA fifth-round pick out of Troy in 2024, Javon Solomon has shown flashes of his pass-rushing ability, but at 6-foot-1 and 247 pounds, he didn't have the ideal size to play defensive end under Sean McDermott. Now with Leonhard taking over, Solomon moves to outside linebacker and Bills On SI's Ralph Ventre says that could help him break out in year three.It won't be easy for Solomon considering the Bills have Greg Rousseau, Bradley Chubb, Michael Hoecht, and rookie T.J. Parker ahead of him. He will also have to contend with Mike Danna, who was recently signed by the Bills to add more depth on the edge. That leaves Solomon with a tough road, and he has to begin to make a name for himself starting with minicamp.Maxwell Hairston, CBBuffalo Bills cornerback Maxwell Hairston enters the field during training camp at St. John Fisher University. | Mark Konezny-Imagn ImagesBuffalo used its first pick in the 2025 NFL draft on Maxwell Hairston, a speedy cornerback out of Kentucky. During his rookie season, Hairston played in 11 games, recording 18 tackles, five pass defenses, and two interceptions.Not everything was ideal for Hairston, however, as he suffered a knee injury during training camp and an ankle injury in Week 18. He enters year two needing to prove that he can stay healthy and also has to fight off second-round pick Davison Igbinosun, who could be a contributor from day one.Landon Jackson, EDGEBuffalo Bills defensive end Landon Jackson warms up during training camp at St. John Fisher University. | Mark Konezny-Imagn ImagesBuffalo's interest in Landon Jackson was the worst-kept secret throughout the 2025 NFL draft process. Unfortunately, the third-round pick from Arkansas didn't make many waves during his rookie season.Jackson played in just three games before suffering a torn MCL and PCL in Week 10, sending him to the IR. He's worked hard to get back and Bills On SI writer Alex Brasky says Jackson could benefit from the change in scheme.Known for his run-stuffing talent, Jackson bulked up while rehabbing and can carve out a role for himself on early downs due to this speciality. Now, he just needs to prove he can stay healthy and make the most out of every opportunity in his second season.Add us as a preferred source on GoogleFollow