Few fans will let the knockout taint the overall legacy Pacquiao has left. Should the Marquez fight be his last, Pacquiao isn't the first, nor will he be the last, to go out like this. It's almost as if every great boxer must end his career on a low note, years past his prime.
When people think of Sugar Ray Leonard, the fights with Marvin Hagler, Thomas Hearns and Roberto Duran come to mind. The losses to Terry Norris and Hector "Macho" Camacho are mere afterthoughts.
Some might be shocked to hear that Evander Holyfield had been boxing as recently as a little over a year ago. The career of Roy Jones, Jr. has failed to come to an end.
Muhammad Ali is the greatest of all time, but even he hung on too long. The defeats to Leon Spinks, Larry Holmes and Trevor Berbick are almost forgotten about. When you think Ali's career, the epic battles with Joe Frazier, George Foreman and Sonny Liston are the fights that come to mind.
The legacies of these guys, and countless others, weren't demonstrably hurt by a few fights too many.
Most fighters are the same. They simply don't know when to hang up the gloves. One punch can change everything. If an aging boxer can just find that punch, they're sure they can still beat anybody in the world.
It doesn't do anything to bolster their career résumés, but it doesn't exactly hurt them either.
Nothing will change how great of a boxer Pacquiao in the years prior to losing to Timothy Bradley and Marquez.
In his prime, Pacquiao was one of the best pound-for-pound boxers in the world. That might not mean as much as it did in the '70s and '80s, but that's still a great distinction to have.
Should his career be over, most fans won't blame Pacquiao for stepping away. He's accomplished almost everything he possibly can and made a ton of money in the process. There's no need to continue to get in the ring taking countless blows to the head.
Even the one unresolved issue on Pacquiao's career—the superfight with Floyd Mayweather, Jr.—is unlikely to be held against him. Many feel that Mayweather is ducking Pacquiao to avoid losing and ruining his perfect record.
Marquez also can't rob Pacquiao of the career he's created for himself outside of the ring.
When the Pac-Man went on Jimmy Kimmel Live and sang "Sometimes When We Touch," he opened himself up to an entirely new audience. Running for office in the Philippines didn't hurt either.