It was a job held largely by one man for the better part of the last decade, despite frequent coaching changes on the defensive side of the ball. Kyle Williams was the primary on-field play caller for the defense's passing down situations.
Now with Williams retired, the sizable responsibility of calling the team's pass rush games up front has fallen on the shoulders of two players.
After careful consideration through the spring, Bills defensive coordinator Leslie Frazier has appointed veteran Lorenzo Alexander to be the primary play caller for the team's pass rush games up front.
But there is a second player who has proven equally capable of making the calls on passing downs and will handle those duties when he's part of the pass rush package.
"When I'm (inside) with Ed (Oliver), it'll be me calling it with that group," said Alexander. "If Harrison (Phillips) rotates in with me as well then I'll let Harrison call it. So it just depends what the package is. And if I'm on the outside whoever is inside will make the call because it's hard to communicate things all the way across from the end position."
Having a veteran entering his 14th NFL season handling those responsibilities is almost expected, but for a second-year defensive tackle, it's uncommon.
"They knew the type of player I was when they drafted me," Phillips told Buffalobills.com. "They tell me all the time my competitive advantage is being smart. I'm not out there with the first unit on pass rush, so I'm not the primary guy like Kyle was, but we'll see when the season comes what the rotation looks like and what different packages we can do. But when I'm out there, I'm the guy calling it."
Phillips proved he could make the right calls in the practice setting in the spring and early in training camp.
"I feel extremely comfortable," said Phillips. "I'm very confident in my abilities there. I followed Kyle Williams around for an entire year and picked his brain more than anyone could've asked me to. He taught me everything I know and I feel very confident. In the offseason I didn't walk away from it. I went through a lot of it in my head. I feel like I can make the calls in a short amount of time."
The Bills defense hasn't unveiled any of these pass rush games in the preseason by design, but Alexander is convinced that Phillips can handle the job when needed.
"He's really good and has a good understanding of it after playing with Kyle (Williams) last year and really picking his brain," said Alexander. "He has a real good feel for it."
Alexander learned how to make the pass rush calls on the field largely through osmosis as a teammate of Williams for the last three seasons. He witnessed how he prepared through exhaustive film study, often on Mondays and Tuesdays during game weeks.
"Each week we always got together and Kyle would tell us how he'd call the games," Alexander said. "Just from me being out there the last few years I learned how he called it hearing him and how he would do it on the field."
Much like quarterbacks make pre-snap checks or changes at the line of scrimmage to get to a better play or protection, Kyle Williams took it upon himself to have counter moves at the ready for certain passing downs that would put Buffalo's defensive line in the best position to succeed.
Now Alexander and Phillips will be entrusted to put Buffalo's pass rushers in the best position to win on key downs in games.
The defensive staff broke things down in the spring for the new players added to the roster in the offseason, knowing this isn't a common practice for most NFL defenses. Having great player attendance during the OTAs in May and early June, enabled every defensive player on the roster to get up to speed on how the calls are made week to week and executed.
"So much of it gets put together on Wednesday or Thursday," said Phillips of installing pass rush strategy during a regular season game week. "That's where you learn what you want to do. Are you facing a scarecrow back there, who is going to stay in the pocket or are you facing someone who is going to scramble? When the quarterbacks do scramble, because they all will, where do they escape to? A gap? B gap? Or do they roll out to their right for their throwing arm? What type of protections are we going to get? Are we getting max protection, are they sliding four-man one way or the other? So just encompassing all that together and then not getting too cute.
"We have Jerry Hughes, Trent Murphy, Ed (Oliver), Lorenzo (Alexander) and Shaq (Lawson) and some other guys who will roll in there. We don't have to get too cute and spin and wrap. If I see Jerry one-on-one, I'm going to say, 'Hey take that, you're going to win nine out of 10.'"
Hughes, who has taken his cue for years from Williams, is pleased with how both Alexander and Phillips have taken on the new responsibility.
"Just watching what those guys do to get ready for the season, going over TV copy of games to gather intel and see what they can learn," Hughes said. "Come Sunday they're ready to make a call and give us a heads up on what the play might be. Then we can play a lot faster."
And to help ensure the on-field calls work as well as they did with Kyle Williams calling the shots in the past, they plan to make use of Williams' expertise through the course of the season.
"Even this year, Kyle will be around," said Alexander. "I'll be getting on the phone and hollering at him asking him what he thinks for our opponent each week. Just because he's going to be helping us out a little bit. We'll all be on the same page by the time the game comes around."
This part of Buffalo's defensive scheming is not a common practice across the league. It's rare to have a player on the field capable of not only digesting up to 30 hours of game film to know inside and out how an opponent lines up, what their tendencies are on certain down and distance on passing downs and who the opposing quarterback relies on the most in certain situations.
"I'd guess two or three, maybe four teams in the league do what we do," said Hughes. "When I first got to Buffalo, I was surprised by all the live calls on the field that we did. It was an adjustment for me. And knowing that most defenses in the league don't do that, it's an adjustment for most teams that play us, which is an advantage for us."
Fortunately for the Bills, two players on their current roster, learned from Kyle Williams, the guy who did it on his own and convinced his coaches he could be effective in executing it.
"For most people on the outside, they think we naturally fall into good plays," said Hughes. "No, we do our homework. We have a scheme and strategy. We want to attack and be effective. We understand that quarterbacks on average get the ball out in 2.4 seconds, so we want to get there in 1.9. It's just about how can most effectively we attack a pass protection? That's our focal point."