KNOXVILLE — Only after four days of traveling and recruiting could Charlton Warren find time to meet the defensive backs he's inheriting.

During Friday's half-hour introduction, Tennessee's new secondary coach told them he's not a typical position coach.

The former Nebraska and North Carolina assistant has a military background. He played at Air Force, then completed his active-duty obligation before returning to the academy to begin his coaching career.

"I had a chance to tell them what I'm about and what I want us to be about as a group," Warren said. "Nothing specific about football — just the mentality, attitude and what I'm looking for in them. Then I gave them a chance to ask me any questions they may have about me and my background. I was in the military for 10 years before I got into coaching, and a lot of their eyes popped out of their head like, 'What?'

"But that's important, because they need to understand what the standards and the discipline and the accountability that I'm going to be about is forged from my years in the service. That gave them a mindset of, 'OK,' they knew who I'm going to be."

With his shaved head and muscular frame, Warren still looks the military part, but he's a football coach with a record of recent success. Nebraska was fifth nationally in passing efficiency defense and 32nd in yards allowed in 2014. North Carolina led the Atlantic Coast Conference in pass defense this past season, and in 2015 the Tar Heels were third in that category while leading the league in interceptions.

Warren was a standout defensive back at Air Force under Hall of Fame coach Fisher DeBerry and helped the Falcons to consecutive seasons with double-digit wins and a Western Athletic Conference title, but he had no intentions of going into coaching.

What he called a "chance meeting" in 2005 with a former coach opened the door. There was an opening on the Air Force football staff for an active duty military member and Warren filled it, launching his career.

Warren said "everything I do" stems from his time in the military.

"The principles I learned way back in those days still apply," he said. "Discipline, accountability, hard work, trust, family, teamwork, brotherhood — all those things, they're not just taglines for me. They were really who I was all those years. I really try to put that on those guys in that meeting room and make them understand there's a bigger picture. We're all here to do a mission. A lot of that carries over to these guys and it resonates with them."

Warren's success and recruiting ties to Georgia — he is a native of Atlanta — made him an attractive option for the Vols, who are tasking him with the development of a handful of young defensive backs and the repair of a secondary that was a weak spot in 2016.

"I am really big on the little things, because to me the little things add up to big things," Warren said. "From the standpoint of secondary play in general, I'm going to be a stickler for technique and fundamentals. There's no thing too little to coach when it comes to technique, eyes, footwork, hands, placement — and it's a process. It's a gradual process, but you instill it, you set a standard and you work it, and that's my plan."

Tennessee was 10th in the Southeastern Conference in pass defense last season, allowing a league-worst 24 completions of 30 or more yards and hemorrhaging big plays due to poor tackling and lackluster coverage techniques.

"It's definitely a clean slate," Warren said. "I'm coming in here with fresh eyes. I'm coming in here with no expectations but hard work. I'm coming in here with no expectations but compete your butt off every play, do what's right away from the building and do what's right in the classroom. I have no expectations except those.

" Whether you were really, really good or really, really bad, it really doesn't matter to me, because now our job (going) forward is to go forth and win. That's what I'm here to do."