OXNARD, Calif. – The Dallas Cowboys' defense has plenty of star power.

Micah Parsons has been the runner-up for Defensive Player of the Year in his first two seasons. Cornerback Trevon Diggs’ 17 interceptions in three years are tied for the most in the NFL since 2020, and he just signed a five-year, $97 million extension.

DeMarcus Lawrence has been one of the better all-around defensive ends in the league, and cornerback Stephon Gilmore was the Defensive Player of the Year in 2019.

Even defensive coordinator Dan Quinn carries weight for the turnaround he has overseen since 2021.

But ask any of those on the defense the importance of linebacker Leighton Vander Esch, the former first-round pick in 2018 who has signed one- and two-year deals the last two offseasons, they all have the same feelings.

“He’s the most important piece,” Parsons said. “That’s one person I was super excited to have back. You talk about someone that knows and commands the defense inside out, making sure everyone is lined up, attention to detail. What he puts into the game can’t be replicated. I mean, he got a chance to work with Sean Lee and I can feel like Sean Lee rubbed off on him. Every bit of his game just reminds me of (it), how he runs to the ball, his aggressiveness, how he just asserts everyone, gets everyone lined up, his willingness to move around.”

Said Lawrence, “He’s a dynamic piece to this puzzle.”

Vander Esch wears the “green dot” on his helmet, with the calls getting relayed to him. It is his responsibility to make sure everybody is lined up correctly. It is nothing to see Vander Esch push a defensive tackle to the left or right to fill the proper gap, then point to a fellow linebacker or safety to make another command all on the same play.

He doesn’t know just his job; he knows everybody’s job. Five years of experience and hours and hours of preparation have led him to where he can see things others do not.

“Knowing everybody’s job, I take pride in knowing that so I can know if we got to get something right on the field at the last second or somebody is lined up wrong or whatever in front of us,” Vander Esch said. “I mean those guys are friggin’ locked in ready to go to the quarterback or ready to get off on the run. And so being able to know exactly where they’re supposed to line up at, the stunts, whatever it may be, the games, the rush patterns, blitz patterns, you’ve got to be able to know all that to get it right. That’s what's fun about being a linebacker because you’re commanding that whole defense.”

Much of Vander Esch’s story is tied to injuries in 2019 and 2020 that cost him 13 games. A neck injury forced him to miss three games last year, but he managed to make 90 tackles, the most since his rookie year when he was credited with 140 and was named to the Pro Bowl.

His absence late last season was felt. After suffering a stinger five snaps into the overtime loss to the Jacksonville Jaguars, the Cowboys allowed 173 yards on 39 carries. In the final four games of the season, the Cowboys yielded 18 pass plays of 20 yards or more (4.5 per game) compared to 25 in the first 13 games (1.9 per game).

When he returned for the playoffs, the Cowboys allowed just 3.8 yards per carry and gave up just five pass plays of 20 yards or more in two games.

“Leighton is a true anchor,” linebackers coach Scott McCurley said. “He’s a true rock in there as far as communicating, being a leader and getting everybody settled in.”

He is also becoming something of a mentor, doing what former linebacker Sean Lee, who played for the Cowboys from 2010-20, did for him. Last year, Damone Clark could not practice in training camp because of neck surgery, but he credits Vander Esch for keeping him involved.

“When I was doing my rehab process, Leighton was a guy that sat in my rehab session with me,” Clark said. “He was a guy that always encouraged me when I was standing on the side sad because I couldn’t be out there practicing with the team. When I got the chance last year, he was smiling from ear to ear, happy for me to be out there. Leighton’s a guy that’s one of a kind. Leighton, he’s more than just a football player. Leighton’s a guy that really cares about you on and off the field.”

On the field this year, the Cowboys are asking Vander Esch to expand his role. He has been lned up on the line of scrimmage as an edge rusher numerous times. When the defensive linemen go through pass-rush drills in the early part of practice, he is right there behind Parsons.

“If you’ve got players like Micah and (Jayron Kearse) that move around, other people have to move around,” defensive line coach Aden Durde said. “So it’s just training people in different skill sets in different situations. It’s not like, ‘Oh, he’s a full-time edge.’ It’s just like giving him the understanding that if you put someone there, if you teach them some fundamentals and some techniques and things they understand that suddenly they can use those skills when the time is called to do it.”

A smile comes across Vander Esch’s face when discussing the new deployment. He had never been asked to play there before this offseason.

“Just taking pride in growing my game and being able to be dynamic and just be a ballplayer really,” he said. “I mean, wherever you can play guys and they can be successful it’s going to be good for the team.”

But his bones are as a middle linebacker, like Lee, his teammate of three years, who commanded the defense and demanded attention to detail.

“Really his intensity, his intensity and focus and effort,” Vander Esch said. “Those three things, you can control every single bit of that. You don’t have to have any talent to do that. So if you focus in on all those areas in meetings, practice, walk-throughs, being the most intense you can be, being the most focused you can be, locked in, and your effort, the rest is just going to take care of itself.”