The official roster cut-down day in the NFL. However, with those roster decisions more likely to be detailed in the final episode, Episode 4 opened with McDermott guiding a late-preseason practice, with the Bills' staff also highlighting what they look for in players to keep them on the roster.

"Hard Knocks" then takes a look at bio-mechanic systems and cameras that are used to break down the Bills quarterbacks' arm motions, including Josh Allen's. Wide receiver K.J. Hamler is once again highlighted as he competes to make the team, and the show looks back on his 2023 pericarditis diagnosis. A spotlight also remains on Ciarlo, who shares how he unexpectedly saw time at nickel in a preseason game, and Frank Gore Jr., who breaks down his relationship with his father.

The episode features a brief segment on DT Casey Rogers helping with a local dog rescue program, then it cuts to general manager Brandon Beane and the front office assessing where they stand on the bubble roster players before a final preseason matchup against the Buccaneers. Prior to the final game action, Allen and some other players sing along to "I Write Sins Not Tragedies," in a highlight sequence.

McDermott sits down for some advice from two NBA Hall of Famers, Vince Carter and Tracy McGrady, who are minority owners of the Bills. The head coach later tells his players that he's proud of them and the work they put in, and the final portion of the episode is footage from the Bills vs. Buccaneers preseason matchup.

Included from the game are shots of Vince Carter briefly talking to Allen, Shane Buechele getting the start at quarterback, tight end Zach Davidson being used as an emergency punter, Tampa Bay's Shilo Sanders throwing a punch and being ejected, Ciarlo recovering a fumble and Buffalo claiming a 23-19 win. 

During a team meeting with McDermott addressing the team. His message is that he wants all phases of the team - the offense, defense and special teams - always to attack. McDermott also reiterates that there are no guarantees in the NFL, and they have to work to be a good team again.

We then see running back James Cook's hold-in end as he signs his extension. He then joins practice in pads to applause from his teammates. After showing clips of Cook running at practice, we get introduced to Ed Oliver and his horses. He has backup running back Ty Johnson with him, and they clean up the stable and ride horses together.

"Hard Knocks' then introduces us to Jimmy Charlo, who played his college ball at Army and was signed a few days before the Bills' first preseason game. He made a big tackle on a kickoff and got praised for it by his team. Charlo tore his ACL in his first preseason game with the Jets in 2024. 

The episode continues with Connor McGovern hosting a pizza party at his house. He was bored during COVID and said he taught himself how to make pizzas. He made them for the team, and they started winning, so he kept the tradition and now hosts the whole team. 

We then go to Chicago, where the Bills will play their second preseason game. There is a joint practice, and a fight breaks out, but it ends relatively quickly with not much drama. The game itself begins, and the Bills get absolutely blown out by the Bears, losing 38-0. 

Fans went in-depth with second-year linebacker Joe Andreessen, who earned the nickname "Buffalo Joe" after growing up a Bills fan then earning a roster spot in 2024. James Cook's contract hold-in was covered, with shots of the running back sitting in meetings but not practicing. Fellow running back Ray Davis got more reps in his absence, including some unique emergency kicker duties. Additionally, some time was spent focusing on receiver K.J. Hamler as he seeks to make his first NFL roster since 2022. Hamler riding a scooter around camp was one of the most viral moments from the episode. Sean McDermott speaking about his past battle with skin cancer, and the head coach also calling former Bills coach Marv Levy for Levy's 100th birthday. Buffalo's quarterback room beyond Josh Allen is another theme, with an eye on the QB2 competition between Mitchell Tribusky and Mike White. "Hard Knocks" also revisited Damar Hamlin's 2023 cardiac arrest on the field and the safety's journey since that moment, including a CPR awareness event at this year's camp and a segment focused on Hamlin sharing his faith as he seeks to write a book. The episode wraps up with the Bills moving out from St. John Fischer University in anticipation of the preseason, then a segment breaking down their matchup against the Giants, a 34-25 loss that included a solid performance from running back Frank Gore Jr.

The first episode of the season saw the Bills players moving into St. John Fischer University. They are one of only five teams still doing training camp at a school. The episode was largely focused on reigning MVP Josh Allen. We got a look at Dion Dawkins' favorite hobby, which is drifting. Fans also got to meet Maxwell Hairston, Buffalo's first-round pick, who is a speedy cornerback. He is getting mentored by the veteran Tre'Davious White, who is back with the Bills this season and vying to get his own ice cream flavor at a local spot. Hairston suffered a knee injury, but initial concern was that he had torn his ACL; however, his ligaments were intact, and he will only be sidelined for a few weeks. Allen took a tour of the new Bills stadium, which is currently under construction. The episode ended with the team's scrimmage, and the footage was set to the team's anthem, "Mr. Brightside."