You could see it from miles away, an enormous image of Amir Khan projected on the 26-story Shell Building, located on the banks of the Thames River. It was New Year's Eve 2005, and Khan was a national hero, at 17, the youngest British boxer ever to win an Olympic medal. He was pictured in profile, staring past the London skyline and into the future, which at the time must have seemed limitless.

But perhaps the gigantic Ferris wheel known as the London Eye, located nearby, was a symbolic reminder that all that goes up must come down.

Canelo Alvarez-Amir Khan Where: T-Mobile Arena, Las Vegas

When: Saturday

TV: 9 p.m. ET, HBO PPV

Saturday at the T-Mobile Arena in Las Vegas (HBO PPV, 9 p.m. ET), Khan won't be thinking about the future. He'll be too busy trying to fend off middleweight champion Canelo Alvarez and salvaging what's left of the present.

Those heady handful of years immediately following the Olympics are gone forever. Although he has had a commendable career and made plenty of money, Khan is no longer the golden boy of British boxing. That accolade now belongs to another British Olympian, heavyweight Anthony Joshua, who won gold at the 2012 London Games.

Joshua is part of a swarm of young U.K. fighters that threaten to eclipse Khan. Heading the list of prime British beef is the beefiest of them all, Tyson Fury, a provocative figure to be sure but also the only lineal world champion among the bunch. The rest are of the alphabet variety, which says more about the state of boxing than it does about their diverse fighting abilities.

Actually, it's quite an impressive assemblage of titleholders from the U.K.: Joshua (IBF), super middleweight James DeGale (IBF), middleweight Bill Joe Saunders (WBO), junior middleweight Liam Smith (WBO), welterweight Kell Brook (IBF), lightweights Terry Flanagan (WBO) and Anthony Crolla (WBA), featherweight Lee Selby (IBF), super bantamweight Carl Frampton (IBF) and bantamweight Lee Haskins (IBF).

A projection of 2004 Olympic silver medalist Amir Khan once appeared on the side of the Shell Building in London during a time when the U.K. fans celebrated him. Bruno Vincent/Getty Images

Although some are gaining on him, Khan is still more accomplished than the brat pack nipping at his heels. Nonetheless, he seems to be sliding backward toward yesterday's news, a once dazzling star flickering like a faulty streetlamp.

Khan's fall from grace has been surprisingly precipitous for a fighter who has lost only three of 34 professional bouts, including a split-decision defeat to Lamont Peterson that was a result of atrocious officiating. Yes, his famously fragile chin cost him dearly against Breidis Prescott and Danny Garcia. There's no getting around that. They've defined him more than all his victories put together.

But aren't British fans supposed to be famous for holding their lovable losers close to their hearts and forgiving their defeats? Henry Cooper, Frank Bruno and Ricky Hatton all retained tremendous support regardless of whether they won or lost. In his first bout after being knocked out by Floyd Mayweather in December 2007, Hatton drew a massive crowd of approximately 57,000 to the City of Manchester Stadium to watch him outpoint Juan Lazcano.

What's going on here? Why hasn't Khan enjoyed similar backing? He certainly doesn't lack courage, as anybody who saw his bruising victory over Marcos Maidana will be forced to admit. If anything, he's too brave, carelessly leaving himself vulnerable as he did in the Garcia fight, which was dead even on the scorecards when Danny drilled him.

It hasn't helped that Khan, like Fury, is an outsider living in a society that has never completely shed itself of a rigid class system and colonial attitude toward cultures other than its own, much in the same way the United States still struggles with racism.

Fury is an Irish Traveller, nomadic people similar to Romani gypsies, both of which have long been the victims of bigotry and persecution in the U.K. It is not because of Fury's loony personality and outrageous ranting that certain factions of British society have alienated him. It's because he's a Traveller.

Khan is a proud Muslim of Pakistani heritage at a time when anti-Muslim sentiment is at an all-time high in the U.K. On July 7, 2005, nine days before his pro debut, Islamist extremists set off bombs in the London underground, killing 52 people and injuring approximately 700 others. Like most of Britain's Muslim community, Khan was horrified by the tragedy and hoped to use his celebrity as a unifying force. He dedicated his fight against David Bailey to the bombing victims and entered the ring carrying the Union Jack. It took him less than two minutes to defeat Bailey in front of a packed hometown crowd at Bolton Arena, but an ugly undercurrent of religious and racial prejudice continued to dog him.

The worst of it was kept in check as Khan cruised undefeated through his first 18 fights. But when Prescott knocked him out in September 2008, racist comments became fairly common. Khan felt disrespected and unappreciated, and he spoke out publicly in 2009.

"Straight after the Breidis Prescott fight, when people said, 'He's finished', there were racial remarks made," Khan said. "I have never experienced face-to-face racism myself, but if you go on the message boards and chat forums there are always people who have to get the religious thing in."

Kevin Mitchell, The Guardian's boxing correspondent, commenting on why Khan spends so much of his time in the U.S., blamed a "small crew of British bigots who have taken against Khan" and driven him out of the country.

"Over there, living quietly and comfortably in the Californian sunshine, he is accepted without question by the fans -- black and white Americans, Filipinos, Mexicans, all of them," Mitchell said.

Amir Khan will move up from welterweight to challenge middleweight champion Canelo Alvarez on Saturday in a 155-pound catchweight bout. Alexis Cuarezma/Getty Images

It's difficult to quantify how much of an effect bigotry has had on Khan's position in Briton's boxing hierarchy. Undoubtedly, some would argue that there's more to Khan's decline in popularity than intolerance and a couple of knockout losses -- that's he's arrogant or full of himself, a common enough complaint about celebrities.

Khan certainly antagonized detractors by saying a fight with unbeaten welterweight titlist Kell Brook would be a "step down." Even so, taken in context the remark was an honest reply about a business decision, uttered while Khan was anticipating a fight with either Manny Pacquiao or Floyd Mayweather. In terms of compensation, it certainly would have been a step down.

Moreover, when fights with Mayweather and Pacquiao failed to materialize, Khan accepted the bout with Alvarez, an opponent who poses a greater threat than Brook. That should count for something.

Of course, people have perfect right to like or dislike whomever they want. It's part of what makes boxing fun. But nobody could fault Khan's generosity.

He spent around £1 million to build the Gloves Community Centre & Gym in a tough section of his native Bolton, and the gym is visited daily by hundreds of economically deprived children. He also established a foundation that raises money for various charities and disaster relief and launched campaigns to promote child safety around British railroads and help end violence toward woman.

Although British boxing is enjoying a virtually unprecedented run of success, it is unlikely Khan will be able to catapult past Alvarez by slipstreaming its momentum. Boxing just doesn't work that way.

VIDEO: Keys to victory in Alvarez-Khan Dan Rafael and Brian Campbell make predictions for Saturday's middleweight title bout between Canelo Alvarez and Amir Khan. Watch

If he is going to have any chance of beating Alvarez, Khan has to frustrate him with lateral movement and a darting attack, never allowing himself to be trapped on the ropes. Trading with Canelo would be inviting disaster.

"I'm not going to stand there giving him free shots," Khan said. "I'll be focused the whole fight to not make any mistakes."

A mistake-free performance is a rare thing in boxing. There is, however, a ray of hope in which Khan can take comfort: The odds against Fury upsetting Wladimir Klitschko were even steeper than those of Khan beating Canelo.

If a big lummox such as Fury can transform himself into Tinker Bell and outbox Klitschko while sprinkling him with pixie-dust punches, nothing is impossible.

The pundits and oddsmakers don't think it's going to happen, but it would be fascinating too see how Khan would be received back in the U.K. if he were to hit the jackpot in Vegas.

Beating Canelo wouldn't necessarily put his face back on the Shell Building, but it would, at least temporarily, keep him a step ahead of the new generation of British boxers eager to take his place.