Rod Marinelli has been coaching since the early 1970s. He got his first college job in 1976 and his first NFL job in 1996. He has been coaching in the NFL since then.

Marinelli joined the Dallas Cowboys in 2013 as the defensive line coach. In 2014 he was named the defensive coordinator. That's a title he still holds today.

Marinelli just turned 70 on July 13, but is still going strong as a coach. In an article by Saad Yousuf of The Athletic, we learn what motivates the coaching legend.

At 70 years old, Marinelli is three years older than the oldest head coach in the NFL, Pete Carroll of the Seattle Seahawks. He’s won a Super Bowl, been a head coach and left a lasting impact. But he still comes back for the daily grind.

“The best thing for me is I love what I do and it comes out. I can’t wait to get to work,” Marinelli said. “I don’t give a shit if it’s (OTAs), training camp; I can’t wait to teach. I adore this game and everything it brings to (players), teamwork but also life skills at the end. I believe in every facet of this game.”

This is the exact kind of coach you should want on your team. He's not doing this for anything other than how much he loves the game. Marinelli loves to teach players — that's something that can have a lasting impact well after he retires.

Those players will benefit from his teachings for their entire lives. He could also teach other younger coaches how to become better teachers to the players. It's a cycle that creates incredible coaches like Marinelli, and incredible players as well.

The football world will miss Rod Marinelli when he eventually decides to retire. However, given how passionate he sounds, that might not be for a while.