PITTSFORD, N.Y. — After two straight early morning practices soaked by the rain, the Buffalo Bills finally got through a training camp session in the sunshine. However, it was clouded by an injury to one of their top offseason acquisitions.Safety C.J. Gardner-Johnson, whom they ticketed for a potential starting role in 2026, went to the ground holding the back of his lower right leg. While the Bills haven’t issued an update, it is the most pressing injury development of their camp early on.What would the Gardner-Johnson injury mean to the Bills, and what could they do in the short and long term depending on severity?Here’s how it looked at practice following the injury, and who they could turn to if they don’t get good news. Plus, some other musings from Day 3 of Bills training camp.Josh Allen discusses DJ Moore additionJoe BuscagliaFallout of the Gardner-Johnson injuryWhether you fall on the optimistic side and take left tackle Dion Dawkins at face value that Gardner-Johnson is “OK,” or are more pessimistic because the team gave no official update after practice, at the very least, Gardner-Johnson will presumably miss some time.Because the injury occurred right near the middle of practice, we got a chance to see how Buffalo’s depth chart looked without him. In Gardner-Johnson’s place, the Bills paired starter Cole Bishop with free-agent signing Geno Stone. Stone spent the last two seasons with the Cincinnati Bengals. At least early in camp, he’s ahead of players like Damar Hamlin and rookie Jalon Kilgore. Second-year player Jordan Hancock has mostly been playing nickel early in camp.Stone signed with the Bills on a one-year prove-it deal, and with less guaranteed money ($187,500), he will likely have to earn his way onto the 53-man roster. This is an incredible opportunity for Stone, who struggled on the Bengals last season, to not only secure a spot on the team in 2026 but to put himself in great position to be the top reserve safety should the Gardner-Johnson injury be one that only keeps him out for a short time.However, if it winds up being a longer-term injury, you do have to wonder how long the Bills will go before seeing what they have with Kilgore mixing in with the top unit.Kilgore, whom the team took in the fifth round, has been mixing into a couple of different roles for the Bills early in camp, with safety being his usual home during team drills. However, working against the backup units, Kilgore has found himself around the ball quite a bit, even picking off an inaccurate Shane Buechele pass on Saturday.That sort of impact has to continue into fully padded practices, which begin early next week, but it’s worth noting given how little the depth chart is defined past Bishop and Gardner-Johnson. Kilgore would need to move past both Stone and Hamlin, but given the draft investment and overall athletic profile on Kilgore, it’s not out of the question if Gardner-Johnson has to miss an extended amount of time. However, it’s very, very early into both Gardner-Johnson’s prognosis and Kilgore’s career.D-line rotation among the first unitOne of the more fascinating things about this Bills roster is how their defensive line would come together under new coordinator Jim Leonhard. It’s a new scheme with the staff trying to figure out which players fit where best.Already from where things were in the first two practices, we’ve seen a bit of movement with that group up front. The players we knew would get plenty of time with the first unit include Ed Oliver, Deone Walker and T.J. Sanders. When the Bills are in their base look with three defensive linemen on the field, unless a signing comes along, that is the most likely trio to start a game. But the group behind that trio is what’s most intriguing to track.On Saturday, there were three other defensive linemen to take reps with the first-team defense and against the first-team offense. That group included rookie Zane Durant, second-year player Landon Jackson and veteran Phidarian Mathis. The notable absence from that group was third-year player DeWayne Carter, after he took several reps with the top unit through the first two days.The Bills mostly sported a two-defensive-lineman look, which syncs up with how things went on Leonhard’s last team, the Denver Broncos, who used three or more defensive linemen on only 38 percent of their snaps when we studied them in April.Although we didn’t see much of the three-defensive-lineman look on Saturday, there was one notable rep that had Walker and Mathis on the field with Durant. And on that snap, it was Mathis, not Walker, who lined up at nose tackle with Walker at 4i (on the inside shoulder of the offensive tackle). Had Walker been with both Oliver and Sanders, he likely would have been the nose tackle.But it’s quite interesting that they are moving Walker around, and that they like Mathis enough to give him those snaps at nose this early. The Mathis and Carter battle for a spot might be the hardest-fought one among the defensive line group this summer, so we’ll see if the Mathis reps with the first unit continue.CB movement at boundary and nickelThe Bills are in search-and-discovery mode with their boundary cornerback group. As we detailed Thursday, it’s a room with questionable depth, and an inexperienced starting option with Maxwell Hairston looking as though he’s in clear control of that No. 2 cornerback job.The Bills continued to try and tinker with the group on Saturday, too. Rookie Davison Igbinosun has been consistently with the second-team defense, which continued on Day 3, but so did some of his troubles.It’s been a very up-and-down camp to this point for Igbinosun. There were a couple of times where he was in on a pass breakup, but those were a bit overshadowed by some busts in coverage. On one play, Joshua Palmer found himself wide open down the left sideline for a touchdown. The play went to Igbinosun’s side, and the Bills looked to be in zone coverage, so it’s unclear whether Igbinosun or Stone, who was in for Gardner-Johnson, was at fault for no one picking up Palmer deep.Maxwell Hairston (left), a 2025 first-round pick, is expected to be the Bills’ No. 2 cornerback this season. (Adrian Kraus / Associated Press)However, the more problematic reps were when Igbinosun was in man coverage and tried to pick up his assignment on a shallow crossing route from one side of the formation to the other. There were two separate occasions that Igbinosun was left a few steps behind his assignment — once against top wideout DJ Moore, and the other against reserve veteran Trent Sherfield. The Bills will be looking for more consistency out of Igbinosun, which will inform Buffalo whether it needs to make a move for a veteran cornerback.Joining Igbinosun with the second-team defense on Saturday was undrafted rookie Kani Walker. He has been an early surprise at training camp, showing impressive athleticism and fluidity despite being a bigger-bodied cornerback at 6-foot-2, 204 pounds. Kani Walker’s chance came with seventh-round pick Toriano Pride Jr. taking some snaps inside at nickel with the third unit, as the Bills attempt to find Pride’s best home within their defense. Kani Walker worked behind Jordan Hancock, who was the second-team nickel all practice.The Bills also mixed in nickel corner Dee Alford at boundary cornerback late in the practice for a rep with the third unit. Rookie wide receiver Skyler Bell got the better of him on a man coverage route but was underthrown by Buechele. The Bills are continuing to see if the answer to their depth concerns is in-house, but the more uncertainty they get from one day to the next, the closer they may be to signing dependable veteran depth before long.Which WRs are getting time with Josh Allen?As we begin to figure out this new-look wide receiver room, one of the more telling things that helps inform where the Bills are leaning early with the group is who works in with star quarterback Josh Allen.Of the receiver group, seven players had at least one snap of team drills with Allen, but there were definitely trends. The four most used receivers with Allen on Saturday were Moore, Keon Coleman, Khalil Shakir and Palmer. It’s not necessarily a surprise those four were the most frequently used. It does confirm that, at least early on, they could be looking at them as their top four when fully healthy.Bell mixed in a bit, but Palmer had more than double the team drill reps with Allen. Bell had much more time with the second and third units. Veteran Mecole Hardman and Stephen Gosnell also mixed in with Allen sparingly.Quick punter competition updateWith one day off from punting in between, the #Puntapalooza returned with the team focusing on shorter opportunities to pin the opponent deep. In total, there were 27 documented punts in team drills between veteran Mitch Wishnowsky and rookie seventh-round pick Tommy Doman Jr., all of which were between the opponents’ 42-yard line and midfield.