PITTSFORD, N.Y. — When Buffalo Bills defensive coordinator Jim Leonhard sat down at the table for his pre-practice interview session on Thursday, it wasn’t just any first camp interview for a new Bills coach.As the team celebrates its 25th straight year at St. John Fisher University for camp, Leonhard has lived the Pittsford life before. The first was as an undrafted free agent in 2005, trying to make an NFL roster for the first time. A relative longshot to make the team, Leonhard defied those odds to crack the 53-man roster in his first season, and remained with the Bills through the 2007 season. After a few stops, Leonhard returned to the Bills in 2013, but didn’t see Pittsford that time around, as he signed in September.Fast forward 21 years later, and here Leonhard is, tabbed as the man to help solve the Bills’ problems on the defensive side of the ball. From undrafted to defensive coordinator with the same team.“In some ways it feels a little full circle. I remember being in these dorms when they weren’t quite as nice,” Leonhard joked, noting all the upgrades over the last two decades.The defensive coordinator firmly believes in the bonding aspect that going away to camp can provide for a team, and it certainly helped him in his NFL journey as a player.“Training camps were always a little bit special,” Leonard said. “Nerve-wracking, right, because you’re high stress and you’re trying to make a team, especially being undrafted. But it is a little of a strange feeling walking around here, kind of feeling like you know it, but at the same time, it’s a totally different feel just with the role I’m in.”Now, as the man in charge of the defense, Leonhard attempts to figure things out on the fly at St. John Fisher, as the team balances learning a new defense and determining the depth at each position within that scheme, all while the staff learns where to best utilize those players.As they begin formulating those solutions, a couple of position groups need answers. Here’s what stood out on Day 2 of Bills camp.The cornerback depth conundrumAhead of camp opening up on Wednesday, going through a 53-man roster projection revealed one very distinct feature. The Bills are light at boundary cornerback — very light. The group consists of the locked-in top cornerback Christian Benford, second-year and 2025 first-round pick Maxwell Hairston, along with rookie second-round pick Davison Igbinosun. Past that trio, the Bills have a rookie seventh-round pick in Toriano Pride Jr. and a pair of undrafted rookies who are longshots to make the team. The Bills usually like to keep four cornerbacks, but there isn’t a clear fourth on the roster as it stands today.While Hairston and Igbinosun are locks to make the team, neither is a sure thing to be a trusted starter opposite Benford. At this point, Hairston has the clear inside track to the job with more time on task and the investment that went into him. They’ve also seen him play in regular-season games. However, Hairston is still an unknown as a starter. In his appearances last season, he made some really flashy plays, which were great, though the down-in, down-out consistency was lacking. Even if he hadn’t suffered an injury late in the season, it was really clear that Tre’Davious White was performing at a higher level than Hairston in his rookie year.In fairness to Hairston, a training camp injury marred his whole rookie year, so he was playing catch-up from August until his mid-season return, which is a difficult thing to do for any first-year player. Now, Hairston gets thrust into a brand new defense in his second season, increasing the degree of difficulty a bit more. However, if there’s one thing that suits Hairston best in this new scheme, it’s that the Bills are likely to play much more man coverage with Leonhard than they had in 2025. That’s exactly how Leonhard sees him, too.“Max is a man corner. He can run, he can challenge,” the defensive coordinator said. “Anytime you have that speed and quickness at an elite level, it allows you to play a lot of man coverage.”Whether Hairston will be an effective starter in the new scheme remains to be seen. With Igbinosun, he’s a rookie at a difficult-to-play position in the NFL. In the interim, he’ll need to prove at the very least that the Bills can trust him to be their first corner in the event of injury. However, that’s a tough thing to glean from only practice reps, which adds to why the entire group past Benford seems to be completely in flux. And why you shouldn’t count out a veteran addition before long if the Bills are feeling like they need some insurance for their young cornerbacks.With the Bills in mind specifically, it all comes back to Tre’Davious White. He was an excellent starter down the stretch of last season, and while the scheme is different this time around, having him as a capable insurance policy for Hairston and Igbinosun would be a massive step for the 2026 roster. Both young cornerbacks have had some trouble over the first two days, but it’s early and the pads aren’t on yet. How they perform over the next two to three weeks, especially when they can be a bit more physical, will be one of the more important things to track in this year’s training camp.Mixing and matching along the DLThe Bills are hard at work figuring out what their defensive line will ultimately look like in their new 3-4 scheme under Leonhard, which involves moving most of their pieces among several positions to determine who and what works best. We’ve seen a steady stream of Ed Oliver, Deone Walker, T.J. Sanders, DeWayne Carter, and even rookie Zan Durant mix in as they rotate. Landon Jackson and Phidarian Mathis have mixed in, too. But the most common four have been Oliver, Walker, Sanders and, somewhat surprisingly, Carter.Walker, in unison with Carter, are the two most interesting pieces of that early top four. Because Oliver and Sanders are far better suited to the 4i position in their new defense, Walker’s ultimate role is up in the air. They know he can play nose tackle in their scheme, but the question is how much they want him to play there versus if he looks more comfortable at 4i. That’s where Carter comes in. If Carter can show well enough at nose tackle, it gives the Bills some optionality for Walker. It means they wouldn’t have to be forced to keep him at nose at all times on three defensive line looks, and could mix Walker into the 4i spot. That’s especially important because Sanders is an unknown himself, in only his second season and with uneven results as a rookie in a different defensive scheme.Much like at cornerback, the group of defensive linemen up front bears watching throughout training camp because of the inexperienced depth behind their starters. Durant played well on Thursday, but they’ll need to see more from him, Sanders, Carter, and Jackson to determine whether they’ll need some external veteran help in that group before the regular season begins. Leonhard said it pretty clearly: They won’t know much about that group until the pads go on and the physicality of the game becomes the focal point.Kyle Allen struggles in the rainOver the last couple of seasons, the Bills have enjoyed one of the better backup quarterback situations across the league. Mitchell Trubisky had enough talent and starting experience in the league to at least steady the ship in the event Josh Allen had to miss time with injury. The Bills just never had to encounter that scenario for more than a handful of plays.