Redskins head coach Ron Rivera and defensive coordinator Jack Del Rio have both been coaching in the NFL since 1997, but it's been rare for the two defensive-minded coaches to see each other on the field.

Prior to Rivera naming Del Rio as his defensive coordinator, the two had coached against each other six times -- only twice during which were they both head coaches. It was even rarer during their playing careers, as they only met four times in college and in the NFL combined.

Their paths crossed, but never joined over the course of their careers. That officially changed last week, and now Rivera and Del Rio bring similar minds and a solitary vision to their first shared coaching venture.

"I've got tremendous respect for who he's been," Rivera said of Del Rio in his introductory press conference. "He's been a very successful coach in this league, he's had opportunities in this league, and he's succeeded in this league."

Despite never playing or coaching together, Rivera and Del Rio have similar backgrounds and strengths. They were both linebackers in college, spent much of their careers in the NFC and became successful defensive coordinators for multiple teams.

As head coaches, both of them were at their first teams for nine years before moving on, and together they bring 21 years of experience leading franchises. That played a part in why Rivera wanted Del Rio on his staff so badly.

"One of the things I tell young coaches is the one thing you've got to have on your staff is a guy that's been there," Rivera said. "I have a saying: don't draw me a map unless you've been there. Well, Jack's been there."

It's been a few years since Del Rio last had a job in the NFL. His most-recent stint was as the head coach of the Oakland Raiders from 2015 to 2017. In his second season, he led them to the playoffs before losing in the AFC Wild Card round to the Houston Texans.

Del Rio spent last season as an analyst for ESPN, where he appeared on shows like "NFL Live," giving his opinion with former coaches Rex Ryan and John Fox. When asked by Voice of the Redskins Larry Michael on "Redskins Nation" about what drew him back into coaching, Del Rio said it was Rivera and his reputation.

"I had the chance to talk with Coach Rivera about it, and I loved the plan that he had in place," Del Rio said. "I loved what I heard about his relationship with [Redskins owner Dan] Snyder and where this franchise was going to go … and I'm excited to be a part of it."

Del Rio admires a lot about who Rivera is as a person, namely the way he treats the people he works with. Rivera believes in treating people the right way; Del Rio loves that, because that is similar to the philosophy he tries to instill in the players under him.

"I talk to players about treating that person like it was your own grandmother with the utmost respect," Del Rio said. "You see that with Ron. He does that, and I admire it. He's a quality man, he was a quality player, he's a quality coach. Everything about him is quality."

Rivera knows who Del Rio is as a player and coach. Like him, Del Rio has a stellar reputation in the NFL as a quality coach with a strong defensive mind, and Rivera wants to rely heavily on him as he takes on the challenge of turning the Redskins back into a winning organization.

"'If you see something wrong, you see something that we need to think about, please tell me because that's the only way I'm going to know,'" Rivera told Del Rio before his press conference.

Rivera and Del Rio's first and only college meeting came in 1983 when Rivera was a senior at California and Del Rio was a freshman at USC. Rivera and the Bears lost to the Trojans on the way to a 5-5-1 season

Rivera was drafted in the 1984 NFL Draft by the Chicago Bears, while Del Rio was drafted one year later by the New Orleans Saints. Rivera was with the Bears for nine seasons and was also a part of the team's Super Bowl XX run in his second year. Del Rio played for 11 seasons with the Saints, Dallas Cowboys and Minnesota Vikings before retiring after the 1995 season.

During that span, Del Rio's and Rivera's teams matched up three times, two of which came in Rivera's last season when Del Rio played with the Vikings.

Both Rivera and Del Rio began coaching in 1997. They both spent their first two years with the teams that drafted them (Rivera was a defensive quality control coach with the Bears, while Del Rio was the strength and conditioning coach for the Saints). They even became linebackers coaches in the same year, as Rivera was with the Philadelphia Eagles and Del Rio was with the Baltimore Ravens.

But their first meeting on opposite sidelines didn't come until Dec. 12, 2004 when Rivera was the Bears' defensive coordinator and Del Rio was the Jaguars' head coach. Del Rio's defense outperformed Rivera's in that contest, as the Jaguars defeated the Bears 22-3.

They met five more times throughout the course of their careers, one of which came in 2011 during Rivera's first season as the Carolina Panthers' head coach and Del Rio's last with the Jaguars. It was the first of two times they met as head coaches of their respective teams.

Rivera's Panthers won the game 16-10. Over the course of their matchups, Del Rio's teams had a 4-2 record against Rivera's.

Now, more than three years after their last in-game meeting in 2016, Rivera and Del Rio are on the same staff trying to turn the Redskins into contenders. The two forming a coaching duo has created a buzz around the team, but Del Rio isn't concerned about all of that. He just wants to win.

"I'm more concerned with the work that goes into putting it all together," Del Rio said. "I'm here to help Ron Rivera in any and every way I can."

Del Rio called himself "a junkie" for winning, and he is working with Rivera to assemble a staff that has that same addiction. From the time Rivera approached him about the job, Del Rio has been all in on his vision of bringing the Redskins back into the spotlight.

But most of all, Del Rio sees being the Redskins' defensive coordinator as an opportunity. It's a chance to get back into coaching and work with a like-minded individual like Rivera whose love for winning rivals his own.

"There's work that has to be done," Del Rio said. "And to me, I'm excited about the opportunity to help this group of young men … grow into a championship football team."