For many NFL fans, John Madden's reputation contains a long list of accolades, from winning division championships to his bust being placed among the league's greatest figures in the Hall of Fame.

All of those are things Washington Commanders' head coach Ron Rivera can appreciate, but his relationship with Madden was a little more unique. He considers himself one of Madden's coaches, even though he never played or coached for one of the league's biggest personalities, because of his mentorship.

At the NFL's memorial service commemorating Madden, Rivera reflected on how important that was throughout his life.

"His support and guidance was truly important to me," Rivera said.

That guidance started decades ago, when Rivera was just a 15-year-old California kid with aspirations of being a professional player. Madden had just led the Oakland Raiders to a Super Bowl XI win over the Minnesota Vikings, and he took his family for a getaway in Monterey, California.

As one of the kids who loved the Raiders, Rivera ran up to Madden and introduced himself. Rivera was hardly the first or the last kid to try and speak to the larger-than-life coach, but Madden gave him a few minutes of his time.

That was when Rivera said, "You know, Coach, I'm gonna be in the NFL."

Madden replied, "Hey kid, go with your gut." It was the first time Rivera had heard that expression, and it carried a heavy significance in his mind. It wasn't until years later that Rivera realized that even then, Madden was coaching him.

"He was showing me what it meant and what you're supposed to do as a coach," Rivera said. "And that's give back and give your time to people. It's a little lesson I learned, but I never forgot that."

Years later, Rivera came to Madden again, this time as the head coach of the Carolina Panthers. He wanted to listen and learn from him as he started a new phase of his career. Naturally, Madden agreed, but before they met, he wanted Rivera to look back at all the games he had lost by six points or fewer (Rivera was 3-13 in those contests).

Rivera wrote "about 15 pages" on what he could have done differently, but when he tried to give it to Madden, he wouldn't take it. "That's not for me. What'd you learn?"

Rivera said he was doing the right thing and going by the book. Madden's response was, "What book?"

"He said, 'Ron, you've played enough football. You've coached enough football. Go by your gut. Go by your instinct. Go by what you know.'"

So, that's what Rivera did during the 2013 season. He started keeping his offense on the field for fourth-down conversions. It worked, so he kept doing it, and soon he started being known as "Riverboat Ron" for his aggressive style.

After starting the year 1-3, the Panthers won four straight games. It was around that time that Rivera got a phone call from Madden.

"Ron," Madden said. "I told you to go by your instinct. I didn't want you to get carried away." That was confusing to Rivera. He thought he was going by what Madden advised him to do. "You gotta do it the right time, not all the time."

Rivera kept that in mind, and his next test came in Week 10 against the San Francisco 49ers, who had won five straight and were coming out of a bye week. It was a tough, low-scoring affair that didn't see the Panthers take the lead until the fourth quarter, but eventually they came away with a 10-9 win.

Rivera got another call from Madden, and this one was a little different.

"Ron, that's what I'm talking about," Madden said. "Physical, downhill football. Smash mouth football at the point of attack."

That kind of praise had an effect on Rivera.

"It really made me feel like I had accomplished something," Rivera said. "I learned something, and I was getting it from him."

Madden, who had just as successful of a career in the booth as he did in his coaching career, passed away eight years later at the age of 85. The league mourned one of its most iconic figures who left an impact on countless players, fans and coaches.

The lessons he gave to Rivera, though, are a piece of his legacy that will be remembered for years to come.

"Coach John Madden was an NFL icon, who played, coached and gave his name to a video game," Rivera said via Twitter. "But to me, he offered his time, wisdom and coaching insight. I was truly blessed to have him as a mentor!"