Perhaps the single greatest rivalry for the Denver Broncos is that with the Oakland Raiders.

It goes all the way back to the start of the American Football League in 1960, with the Raiders being the first opponent ever to play in Denver. The Broncos had played all their preseason games on the road, and opened their home schedule in Week 4, in old Bears Stadium, on Oct. 2, 1960.

The Broncos beat the Raiders 31-14 in front of 18,372 curious fans welcoming pro football to Colorado.

But one single individual who suited up that day is still active with his team 60 years later.

That would be Tom Flores, Oakland's first quarterback, who completed 10-of-15 passes for 124 yards and ran four times for 78 more against Denver in that first game.

"Coach," as a lot of us still call him, remains with the Raiders today as a consultant. He was uncertain as to whether or not he would attend this week's game, but Tom Flores is always there in spirit.

Tom Flores has had a lot of firsts in his career, including being the first Hispanic quarterback, and later, head coach, general manager and team president in pro football history.

It goes without saying that each of his accomplishments add onto that list of firsts.

Less than one decade removed from having been a farm worker, Flores played college football at University of the Pacific in Stockton, but he had a rough go of it before beginning his career in pro football with the Raiders.

He actually saw the first extended action of his "pro" career with the minor league Salinas Packers after he was cut by the CFL's Calgary Stampeders in 1958. He also attempted to land with the Washington Redskins before even getting a chance with the expansion Raiders. 

Flores was happy to have a job, a shot at pro football when he and the Raiders started out.

The future would have been beyond impossible to predict on Oct. 2, 1960, but Flores eventually earned four Super Bowl rings, one as a backup to Len Dawson of the 1970 world champion Kansas City Chiefs (Super Bowl IV), one for winning the Super Bowl as an assistant coach with the 1976 world champion Raiders (Super Bowl XI), and two as a head coach with Oakland.

He led the Raiders to two Super Bowl victories, in 1979 while in Oakland (Super Bowl XV) and in Los Angeles in 1982 (Super Bowl XVIII).

Flores always seems so cool, calm and collected on the sidelines, but his outward demeanor hid an inner passion. His nickname to many was "The Iceman," but he had an inner drive that few could imagine.

In fact, his autobiography is titled "Fire in the Iceman."    

He and Mike Ditka are the only two people in NFL history to win a Super Bowl as a player, assistant coach, and head coach.

From 1997 until 2018, Flores served as a radio announcer for the Raiders Radio Network, so he made annual trips to Denver in that capacity as well.

He is the only individual ever to appear in Denver "against" the Broncos as quarterback, assistant coach, head coach, and member of his team's broadcast crew.

And now he is a consultant, spanning all sixty years of Broncos and Raiders history in pro football.

One of Tom and Barbara Flores' sons lived for years in the Denver area and he would enjoy getting together whenever the Raiders visited here. 

We shared many a visit in the Raiders' broadcast booth, and it is impossible not to like and have great respect for Tom Flores.

He has noted to me many times how much Denver has changed since 1960, both in the growth of the Mile High City and in terms of the change from old Bears Stadium, to Mile High Stadium, and now to Empower Field at Mile High, adding that "One thing that has never changed is the passion of the fans here. Even when the Broncos were not very good in those early years, the fans were always loud and supportive.

"Then, of course, Denver became a playoff team and a fierce rival," Flores added. "Then you got John Elway. The rest is history, but the fans have always been here."

Just recently, Flores was named a finalist for the Pro Football Hall of Fame's Class of 2020 Centennial Slate.

Naturally, I think he is an excellent choice, but that is matter for the Hall of Fame blue-ribbon panel of selectors to consider.

Any time you have a great rival team, you are fortunate. When one of the most significant people in the game's history represents that rival for six decades, it is most remarkable indeed.

On Sunday, the Broncos welcome Tom Flores' Raiders to Denver, as one of the legendary rivalries in the NFL closes out the season in the Mile High City.