The last time he got in the ring, he fought an unimpressive bout against undefeated Timothy Bradley. Not that Bradley dominated him or won the fight, but Pacquiao didn't really assert himself in the ring and merely looked like he was going along for the ride, content to take an uninspired decision.
It didn't turn out that way.
Even though Pacquiao appeared to win 10 of 12 rounds, the decision was taken from him by judging that was questionable at best and indefensible at worst (source: SBNation.com).
As far as Pacquiao's legacy is concerned, the Bradley fight will largely be forgotten and won't matter in the long run.
Pacquiao will be remembered as a hard-working and skilled champion who fought many of the best fighters of his era and almost always came out on top. When it comes to staying busy in the ring and throwing hard and accurate punches, few can match the left-handed Pacquiao.
He has fought many excellent fighters, including Juan Manuel Marquez, Marco Antonio Barrera, Ricky Hatton, Miguel Cotto and Antonio Margarito. He also has defeated world-class fighters including Oscar De La Hoya and Sugar Shane Mosley.
The wins over De La Hoya and Mosley helped build Pacquiao's reputation more than any other of his fights.
That's enough to get Pacquiao in the discussion with the best lightweight, featherweight and welterweight fighters of all-time.
Yes, his name will be discussed with the greatest fighters, but it's not likely that 20 years from now anyone will pound their fists against the table and declare Pacquiao to be among the best.
Could he get in the ring with the likes of Sugar Ray Robinson, Roberto Duran, Sugar Ray Leonard and Thomas Hearns? Sure, but would he have beaten any of them by knockout or a decision? Hardly likely.
In a discussion with BoxingScene.com, Leonard tended to be respectful of Pacquiao's ability, but stopped short of saying he could have beaten Robinson, Duran or himself.
However, Pacquiao still has a chance to step up his reputation further. If he were to get the long-discussed, much-anticipated but yet to be realized fight with Floyd Mayweather, Pacquiao would have a chance to be taken far more seriously.
Mayweather is generally considered to be the best fighter of his era. When it comes to speed, defense, skill, style and punching power, Mayweather appears to be without peer.
He does rank with the great champions mentioned above.
He has been working at his craft since his early childhood, but he too lacks the great opponent that often helps top fighters make their reputations.
Will Mayweather ever give Pacquiao the fight that would enhance both their reputations? It seems that if it was going to happen it would have already been signed, sealed and delivered.
It's not completely out of the picture, but it's probably more likely not to happen.
That would be too bad. It's the one potential event that would deliver boxing to the front page of every newspaper and website in North America.
It's the fight that would help Pacquiao grow his reputation from top-level fighter of his era to a potential all-time great.
Of course, he would need to beat Mayweather for that to happen and he would clearly be a decided underdog.
But with the speed of Pacquiao's hands and his courage in the ring, he would have a solid chance to earn a spot with the all-time greats.