PHILADELPHIA -- Sean Mannion kept two playbooks as a backup quarterback. He studied the Vikings' edition, which he needed to master as Kirk Cousins' backup in Minnesota in 2023. Then, there was the binder full of plays he accumulated for the living playbook he designed for when he would eventually lead an offense.
The collection started early. Mannion's home includes a framed yellow notepad on which he sketched plays as a 7-year-old at his father's football practices. His college coach at Oregon State, Mike Riley, remembers a "monster video study" of passing concepts dating back seven decades.
So, when Chris Kuper, then a Vikings assistant and now the Philadelphia Eagles' offensive line coach, fielded Mannion's questions about protections in 2023, he recognized Mannion's preparation as Cousins' understudy. Those questions were also preparing Mannion for his current role: Eagles offensive coordinator.
"I figured he had an inkling that maybe it might be something he wants to do," Kuper said, "and now we're seeing it."
Mannion's first official game as an offensive coordinator is perhaps the most anticipated Eagles debut this weekend, given the stakes of the hire and the curiosity surrounding the 34-year-old. Coach Nick Sirianni needed a new offensive coordinator for the fifth consecutive season after the offense's regression in 2025 prompted the biggest change of the Sirianni era.
The search initially focused on an experienced play-caller. It eventually led to an opposite profile: the former NFL quarterback with only two years of coaching experience and no NFL play-calling experience.
Much of the attention has focused on Mannion's new scheme, with roots in the Sean McVay system. That was part of the appeal for Sirianni. But in the NFL, if you're chasing a trend, you're often late. Mannion's success won't be based primarily on scheme. It will depend on a football mind cultivated long before he became a coach. McVay's luster is not necessarily about his playbook, but his brilliance in implementing it.
That's what the Eagles are beginning to witness.
"If I were to lock the three smartest people in the facility in one room, Sean would be there," offensive tackle Jordan Mailata said, "and I think Sean will just be by himself."
Mannion's "born-to-coach" narrative belies how he's long been known in football circles. When you're a 6-foot-6, 230-pound, four-year starting quarterback in the Pac-12 with more than 13,600 passing yards and 83 touchdowns in the profile, coaching can wait.
Mannion wasn't making airport runs in his early 20s while working the grunt job of a low-level staffer. Yes, Riley saw coaching in Mannion's future. But Mannion was busy throwing for 481 yards and four touchdowns against Cal (and eventual No. 1 pick Jared Goff). The focus then was on the Saturday game plan.
It's why the distinction between man and scheme matters. The football mind was apparent during weekly preparation and the quick processing on the field at Oregon State. Mannion made adjustments with eventual first-round pick Brandin Cooks in between plays based on the defense's presentation. He consumed the game plans -- "Nobody surpassed him," said Riley, who coached multiple NFL quarterbacks in Corvallis, Ore. -- and banked what resonated with him.
"This is what I think is important in coaching -- to have a diverse background in what people do," Riley said. "And then you have to be selective in what you're going to do. Through study, coaches come up with or select a group of things that they like. But you have to have an inventory behind them, and that's what Sean was doing."
Mannion was a 2015 third-round pick by the St. Louis Rams and joined a quarterback room with Nick Foles as a rookie. Before his second season, the Rams traded for the No. 1 pick and drafted Goff. The 2017 season was transformative for Mannion. It wasn't because of how he played, although Hall of Famer Eric Dickerson said during a pre-training camp interview that the Rams should start Mannion over Goff. It was his exposure to McVay, along with an offensive staff that included future NFL head coaches Matt LaFleur and Zac Taylor.
"I just felt like I was learning so, so much," Mannion said. "It was such an exciting way to match the run and pass. They had such a way about teaching the game where we could feel ourselves challenging a defense, but it felt simple to us. Those are the things that really stood out to me going through that experience that really resonated with me as a player and certainly resonated with me as a coach. That was a very exciting point in my football life, just the exposure to that type of teaching, that type of scheme."
He soon began the journeyman life of an NFL backup, bouncing between Minnesota and Seattle from 2019 to 2023. He was exposed to offensive minds with head coaching jobs on their resumes, including Gary Kubiak, Kevin O'Connell, Kevin Stefanski, Klint Kubiak and Dave Canales, plus a number of future offensive coordinators.
Mannion transitioned from potential starter to veteran backup, offering answers and support in the meeting room, seeing the game through the starters' eyes. Kind of like a coach. Those years became an incubator of offensive ideas, pulling leaves from different branches of the scheme and adding plays and ideas to the binder that would soon blossom in Philadelphia.
"Very, very obvious early on that he was going to be a coach the minute he decided he was going to stop playing," said Stefanski, who was Mannion's offensive coordinator in 2019. "I think great coaches come from that (backup) role because you have to prepare yourself to play, even when you're not getting the reps. So, I think he's been really developed into it. … Developed by the different stops that he's had, by the different people that he's had. But it's always been in him to coach."
Mannion moved from the quarterback depth chart to a coach's office, joining Green Bay's staff in 2024 and working under LaFleur. He was promoted to quarterbacks coach after one season, tasked with preparing both Jordan Love and Malik Willis to win games. It's an example of adjusting to personnel and flexibility within a scheme, molding to players as Mannion is expected to do in Philadelphia. The Packers did not want to lose him.
"Not shocked that it happened that fast because of the way he works," Packers general manager Brian Gutekunst said. "Usually when you bring in a young, really talented coach, you're kind of hoping to have him for a number of years, and that's unfortunate for us, but he's going to do a great job. The ability to see the game through a quarterback's eyes because of his playing career, coming from a coaching family, there's just a lot to like there."
Mailata left his first meeting with Mannion calling his new offensive coordinator an "evil genius," fitting the profile of the wunderkind play-callers who have become vogue around the NFL.
Part of it might have been the scheme change -- "It's basically been the same offense every year. This is different," defensive coordinator Vic Fangio said -- but it went beyond new concepts such as more under-center plays and the wide-zone running scheme.
What mattered to Mailata was how Mannion explained it.
"I think when we're being taught the scheme, just the explanation of how the defense is going to see it and what the plan is," Mailata said. "You see it, and you're like, 'That's actually pretty smart, why didn't I think about that?' … You may not understand it at the time, and then you go through the meetings, and he breaks down everything. There's a purpose to everything in the plan. You see the defense kind of confused -- who's covering who in this motion, how does that affect the D-line and O-line, the run sell."
Eagles center Cam Jurgens said Mannion's strength has been "talking through (the offense), why it should be a certain way." Veteran tight end Johnny Mundt, who played with Mannion in Los Angeles and Minnesota, described it as "thorough and very clear." Quarterback Jalen Hurts, whose connection with Mannion matters most, used the same term -- "clear" -- when discussing Mannion. He identified Mannion's vision. Hurts likes to know why. Mannion offers answers.
"He understands how he wants to play," said Andy Dalton, the Eagles' reserve quarterback who is four years older than Mannion. "And he's also a really good teacher. When he's in front of the room and he's explaining things, he gets all the little details he needs."
Dalton is in his 16th NFL season and watched Mannion's progression toward play-calling. He's in the same quarterback fraternity, a group exposed to enough coaches and coordinators to spot substance.
Riley expected Mannion's time as a player would be "invaluable" when facing the room. Wide receiver Dontayvion Wicks, who overlapped with Mannion in Green Bay, never heard Mannion talk so much. Sirianni's been impressed by the attention Mannion commands and his ability to connect with different position groups.
"The thing that I didn't get to see, because I was a coach and he was a backup quarterback, is his ability to lead and lead men and lead coaches," Kuper said. "He's an organized person; he knows what he wants; he's very clear and concise. So the job description is very black and white, which is what we all want."
Mannion is intentional with how he devotes his time in meetings and on the practice fields. He sneaks into the quarterback meeting room during special teams meetings. He otherwise tries to bounce between positions. This is when he's a coach's son -- not just the former quarterback.
Sometimes you might forget he was once that pass-happy quarterback at Oregon State. The Eagles needed to invigorate their passing offense, yet this offseason there's an internal sentiment about a revitalized run game. Kuper said Mannion does not simply have a "passion" for running the ball; he has an "aptitude" for it. Kuper even guessed Mannion could game plan and call a game just for rushing.
"He sees the game from a 30,000-foot view, as well as being on the sideline and being into it with the players," Kuper said. "I think it speaks volumes. His experience as a quarterback in this league and being able to connect people and become a glue guy has been incredible."
This is not to suggest it's going to be seamless. Riley expected an adjustment with play-calling. Mannion put himself in the shoes of the play-caller during games as a player and coach, considering what he would call on that third-and-long or in the high red zone or against a certain blitz. Mannion alternated between the sideline and the coaching booth in preseason games and the Eagles' open scrimmage to determine where he's comfortable.
The Eagles did not game plan specifically for preseason games, so his first time planning and sequencing the calls comes Sunday against the Washington Commanders. Early feedback on the operation was favorable. Quarterbacks appreciated how quickly they heard the play call. The call sheet appeared organized. Communication remained sound. Substitutions were clean.
Mystery still exists. The scheme, which the Eagles consider a competitive advantage, will evolve as Mannion sees how it fits the personnel. But Mannion's success will depend on more than the binder he put together. It hinges on how he puts those ideas to work.
"As the year goes on," Mailata said, "we get to display what's in the beautiful mind of his."
This article originally appeared in The Athletic.
