DENVER — The final chapter of the greatest quarterback rivalry in NFL history plays out in all likelihood Sunday with the 17th meeting between Tom Brady and Peyton Manning.

New England and Denver play again next season, but Manning is expected to have received his gold watch — and maybe another silver trophy — by then.

In that case, Sunday’s showdown in the AFC championship between the Patriots and Broncos would mark both the crest and the culmination of a clash that defines the two quarterback greats who transformed the game and transcended the sport.

“This is Jesse James and Wyatt Earp standing out in the street at high noon for the last showdown,” Joe Theismann said. “You’ve got arguably the two greatest players that ever played the position. Peyton revolutionized the game and Tom, through his championships, has proven he’s the best that’s ever played the game.”

Their respectful rivalry — they’re neither best buddies nor mortal enemies — began on a cloudy afternoon in Foxboro Stadium on Sept. 30, 2001, and grew into something on par with Arnold Palmer vs. Jack Nicklaus or Wilt Chamberlain vs. Bill Russell.

“Our sports society is built around stars, and stars draw people to the game, those are the players they want to watch. You want to watch Ali and Frazier, Bird and Magic, Brady and Manning,” said Tony Dungy, the coach of the Colts for Manning’s only Super Bowl win. “We are seeing two just top-tier guys and everyone will root for one and against the other and pick sides and argue who is the best. It draws people, and it especially draws the casual people to the game.”

This generation of football fans may never see anything like it again.

“Every football fan should watch this game because very seldom in life do you get to see two competitors as great as they are with this much at stake,” Theismann said. “It’s what’s at stake that makes this one more interesting.”