It’s tough for top-tier NFL quarterbacks to add to their legacies when they leave the team that made them famous, but Peyton Manning’s giving it a shot in Denver. (AP/Stephan Savoia)

Matt DiCarlo traveled across the country to see Peyton Manning’s first game against the New England Patriots as a member of the Denver Broncos. Tailgating outside Gillette Stadium in Foxborough, Mass. last Sunday, DiCarlo stood out in a bright orange Broncos jersey.

“In my mind, he’ll always be an Indianapolis Colt, but we’re really excited just to bring him in and hopefully get us to another Super Bowl,” the Littleton, Colo. resident said.  “Yeah, in my mind he’s always a Colt.”

Which might explain why DiCarlo and another Broncos fan, Chris Kusick, were wearing jerseys bearing the name and number of another Denver quarterback. John Elway will always be a Bronco even if he leaves his current job in the team’s front office.

“I actually became a Bronco fan because of John Elway, followed the team, and [I’m] still a huge fan,” the Bridgeport, Conn. resident said. “I probably would have been crushed if he had [gone] and played somewhere else.”

Baltimore Colts legend Johnny Unitas ended his career in 1973 with the San Diego Chargers. (AP)

Baltimore Colts legend Johnny Unitas ended his career in 1973 with the San Diego Chargers. (AP)

Fans enjoy the luxury of toggling between very long and very short memories whenever it’s convenient. But for Peyton Manning the change is more complicated. After 14 years, the Colts chose Andrew Luck’s bright future over the 36-year-old Manning’s brilliant past.

“I don’t have anything else to compare it to, but it’s not easy. It is a transition and it’s one that you continue to go through,” Manning said when asked about change after Denver’s loss to New England. “It’s the first time it’s ever happened [to me] and I’m kind of going through it, so I could probably give you a better answer later on as more time goes by. But it’s definitely different, no question about it.”

Patriots fan Mike Lucie says if Tom Brady was in Manning’s cleats, he’d wish him well.

“To me it’s not just shutting a light switch off and saying all of a sudden, ‘Oh, he’s playing for another team. I can’t like Brady.’ You can still root for the individual,” Lucie said. “I would still root for the team. So, if  Brady came back and played against the Patriots, I’d still have to root for the Patriots. I wouldn’t think anything less of him if he went to another team. It is a business.”

As for Brady himself, switching teams is a scenario he’d rather not consider.

“Honestly, I haven’t thought about it. Really, I haven’t had the situation,” said the 35-year-old quarterback. “Hopefully it never happens.”

San Francisco 49ers great Joe Montana closed out his career in Kansas City. After Montana arrived in 1993, he guided the Chiefs to the AFC championship game.

Jeffrey Flanagan is a columnist for Fox Sports Kansas City and the author of A Sea of Red: 50 Years with the Chiefs and The Kansas City Star.

“Who are you going to remember Joe Montana for? Even though he had two pretty good years here, he’s always going to be remembered as a 49er.”

Montana’s two seasons in K.C. fell short of a Lombardi trophy, but fans cling to the memories.

“The last time this franchise won a playoff game, Joe Montana was under center,” Flanagan said. “That’s how long [it’s been]. That’s how desperate this franchise has become.  And it tells you how important a guy like him is.”

Like Montana, Brett Favre will forever be associated with the one team he helped to win it all: the Green Bay Packers. But like Favre’s retirement – or retirements – his one-team legacy comes with asterisks. There’s the double hop to the New York Jets then Minnesota before finally calling it quits, but Favre’s forgotten legacy is with the Falcons. The gunslinger spent his first season in Atlanta in 1991.

Joe Namath is remembered for his days with the Jets, but for his final season he was in Los Angeles, often on the Rams' bench. (AP)

Joe Namath will always be a Jet, but he spent his last season with Los Angeles, often on the Rams’ bench. (AP)

In sports, like in life, all good things must come to an end and some of them should end sooner than they do. In 1958, Johnny Unitas and the Colts beat the New York Giants to win the NFL Championship.  But in 1973, at the age of 40, Unitas spent one season, his last, with San Diego. One of his teammates was a rookie quarterback just starting what would end as a one-team, Hall-of-Fame career: Dan Fouts.

In contrast to Unitas, Flanagan thinks the new scenery in Denver gives Manning a chance at history. He could do something no other starting quarterback has ever done.

“Can he go win another Super Bowl with another franchise? Joe Montana got to the [AFC] title game … Brett Farve got to the [NFC] title game with the Vikings,” Flanagan said. “It would have been interesting to see their place, their legacy, if they had actually won the Super Bowl with their new team.”

Whether or not that happens, with two Super Bowl trips and one title in Indy, Manning’s legacy is secure. And for quarterbacks who have won it all, the low moments tend to fade away.

After all, when’s the last time you saw a picture of Joe Namath sitting on the bench for the 1977 Rams?