The casual fan doesn't appreciate him for the great fighter he is. Part of the reason for his lack of widespread notoriety—especially in the United States—is his spotty English. It's an issue many foreign fighters face, and it unfairly hurts their popularity.
Some of it is because it's hard to get behind a man who admits to drinking his own—or anyone else's— urine.
Though he has since said that he's stopped that aspect of his training regimen (per ABS-CBN News), needless to say, it may have left a bad taste in the mouth of boxing fans, so to speak.
Aside from those two nuggets that serve as fan discouragement, Marquez is an amazing fighter. He's compiled a record of 53-6-1 with 39 KOs. Most casual fans know him for his three epic battles with Pacquiao, but he has accomplished plenty aside from pushing Pacquiao to the brink.
Take a look at some highlights from his career:
Marquez has won seven world titles in his career, and he's beaten the likes of Juan Diaz (twice), Joel Casamayor, Orlando Salido and Marco Antonio Barrera. Still, his career is marked by the fighters he's lost to more than the ones he's defeated.
He's come up short against Pacquiao, Floyd Mayweather, Jr. and even Chris John.
At 39 years old, he doesn't have a long career ahead of him. He is writing the last lines of his boxing legacy now and possibly over the next few years.
With all he has accomplished, he could gain his highest measure of fame with a win on Saturday. He'll have captured his signature win, but he will have also knocked off one of the biggest names in the sport.
That will automatically line him up for a huge payday. That's something that has eluded him much of his career. In his third fight with Pacquiao, Marquez took home $5 million (per ABS-CBN News).
According to ABS-CBN, he will earn $3 million for Saturday's clash.
The $5 million was the highest purse of Marquez's career, but he'd stand to make a sizable amount in his next fight if he beats Pacquiao. Marquez is likely headed for the Hall of Fame when he hangs up the gloves, win or lose on Saturday night.
He's in the enviable position of having nothing to lose but everything to gain.
Follow Brian Mazique and Franchiseplay on YouTube and Twitter for reactions, analysis and news from the world of sports and sports video games