INDIANAPOLIS -- When news spread at 9 a.m. ET Tuesday that Buffalo Bills defensive coordinator Leslie Frazier was taking a year off from coaching, the decision was met with surprise around the NFL world.

That extended to pass-rusher Von Miller, who found out by a phone call from coach Sean McDermott that Frazier, 63, would not coach next year but planned to return in 2024.

"I didn't see it coming," Miller said Friday from the NFL scouting combine. "He had a great year with us last year, and he had several great years the whole time he's been there. So, I didn't see it coming, especially the timing of it. Usually, you know, coaches take, they [usually] come to a decision like right after the season when there's jobs available. But Coach Frazier, he's vested in this league. He's a Hall of Fame player, Hall of Fame coach."

Frazier's decision was not made for health-related reasons, but instead, as McDermott told Miller on their call, "he just needs to take a year off." General manager Brandon Beane said they weren't sure if Frazier's return would definitely be with the Bills.

"It's tough. It's a hard business, as we know," Beane said. "There is a lot of scrutiny on it, and there is a lot of hours, a lot of time put in. Again, not speaking for Leslie, but sometimes you may just want to take a breath from them. That would be for him to say, but he was very adamant that he was not going to retire. My two cents: He just wanted to take a step back this season."

Frazier interviewed for head-coaching opportunities in 2020 and 2021 after being interim head coach and then head coach of the Minnesota Vikings from 2010 to 2013 (21-32-1 record). He was passed over for interviews this coaching cycle. Since 2017, the Bills defense has been No. 1 in the league in defensive efficiency (60.88), yards per play (5.04) and touchdowns allowed per attempt (3.3%).

Miller's follow-up question for McDermott: Who would call plays on defense for the Bills?

"But [McDermott] said, ‘we’re fine.’ Either it'll be Coach McDermott, or they'll find somebody within," Miller said.

Beane has said they always try to look internally when hiring first before looking outside for all positions. The Bills have a variety of internal options, with McDermott taking over getting strong consideration. They also have assistant coaches with defensive playcalling experience: recently hired senior defensive assistant Al Holcomb and senior defensive assistant/defensive line coach Eric Washington.

McDermott has the most experience, with eight years spent as a defensive coordinator (two with the Philadelphia Eagles and six with the Carolina Panthers).

"The good thing for us is Sean's background. Sean's been a longtime defensive coordinator and so right now he'll just kind of lead that and not saying that we would, or we wouldn't [hire a new coordinator]," Beane said. "It's still very early in the offseason. ... We feel we got some really good minds in that room."

What if it's McDermott?

While Frazier has called the defensive plays, McDermott has played an integral role in the team's defense, meaning the scheme likely wouldn't change.

"[McDermott's] in there, we go over stuff, especially if it's a game that we won and there were some mistakes that we made," Miller said.

The pass-rusher noted how after the Bills' Week 11 win over the Cleveland Browns, McDermott -- whom Miller described as "naturally fiery" -- met with the defense to review what happened after the Bills gave up back-to-back touchdown drives at the end of the game.

"Whether it was me, it was plays that I should have made, or whether it's [defensive backs] Taron Johnson or Dane Jackson, he went through every single play and said, this is why this happened," Miller said. "All you can do is just respect that and I appreciated that a lot."

It would not be McDermott's first time calling defensive plays for the Bills. In 2018, McDermott took away playcalling duties from Frazier at halftime of a September loss to the Los Angeles Chargers, but that was short-lived with the coordinator taking back over the responsibility the next week.

One of the coaches McDermott learned under, Kansas City Chiefs coach Andy Reid, is known for calling offensive plays successfully while also managing all of the head coach's responsibilities during a game.

Three other NFL head coaches call the defensive plays for their team: Dennis Allen (New Orleans Saints), Todd Bowles (Tampa Bay Buccaneers) and Brandon Staley (Chargers).

Miller played under Vic Fangio, who called defensive plays in Denver.

"If anybody can do it, it's Coach McDermott. It's been done before. Coach Fangio ... he was the head coach and the DC. So, it's just, we'll be good. You know me, I'm the most optimistic."

If McDermott were to transition into the Bills' full-time defensive playcaller, how he's able to manage the game and distribute other responsibilities would be another tough test for him as a head coach.

"If Sean decided to take over the playcalling, I've seen him do it for a long time, great success," Beane said. "He's gone against some great quarterbacks in his day and offensive gurus that you have to beat. That would be great if that's the route he feels is best for us, I'm going to support that and have full faith that he would do a great job if it came to that."

What about other in-house candidates?

Washington has been on the Bills' staff since 2020, serving primarily as the defensive line coach. He worked with McDermott in Carolina from 2011 to 2016, before taking over the Panthers' role as defensive coordinator in 2018, a role he held for two seasons. Washington, however, had playcalling responsibilities taken away by coach Ron Rivera during the 2018 season, a situation that continued in 2019.

During Miller's time in Buffalo, he spoke glowing of working with Washington and how he handles the defensive line room.

"When you look through Coach Washington, you know, that s--- is real. He was in the military, the way he speaks. .... And it's love first. Love is the foundation of all that," Miller said.

Holcomb was hired a month ago and was most recently the Panthers' interim defensive coordinator. He was also the defensive coordinator for the Arizona Cardinals in 2018 and called played for both the Panthers and Cardinals. He overlapped with McDermott in Carolina from 2013 to 2016 as the linebacker coach.

"[Holcomb's] coached multiple positions on the defensive side," McDermott said. "He was with me on the staff in Carolina when we went to the Super Bowl. So, he was a great addition, I thought, and when they were changing over down there, he freed up for us."

The team could also consider linebackers coach Bobby Babich and defensive backs/passing game coordinator John Butler.

However the team decides to organize the defensive staff, there is confidence in the ability to carry on their recent success.

"We think we've got a very good defensive staff, a lot of bright minds in there, and it's a just a matter of who is going to assume what roles to handle this going forward," Beane said, "but I do not think it's a setback."