Eight division world champion Manny Pacquiao says the outcome of his July bout against heavy puncher Lucas Matthysse will likely determine whether he will hang up his gloves after a storied career.
After a one-year hiatus from the ring, the 39-year-old has started training two weeks earlier than usual to bring himself up to peak fighting condition.
"I am not saying it will be the last, but it will be the basis for (me) to think about (whether) to continue or not. So I am trying my best and doing our best in the training in this fight to show if I can still do it or not," Pacquiao told AFP.
Pacquiao has won world titles across an unprecedented eight different weight classes, but critics -- including Matthysse, who is four years his junior -- question his ability to box at the top of his game due to his age.
The fighter, who won 38 of his first 47 professional fights by knockout, has not knocked out an opponent in nearly nine years.
The two will face off for the World Boxing Association "regular" welterweight belt on July 14 in Malaysia.
The fight comes a year since the southpaw lost his World Boxing Organization welterweight crown in a shock points defeat to 2012 Australian Olympian Jeff Horn - who came into that fight as a huge underdog.
In contrast, Matthysse won the vacant WBA belt after beating Thailand's Teerachai Sithmorseng in January.
"(Matthysse) is a very aggressive fighter. I am not worried about his style. My worry is I need to get 100 percent conditioned -- the stamina, the power and the strength to survive the 12 rounds," Pacquiao said.
One of the flaws that hurt Pacquiao in the contest with Horn, is the claim that the Filipino veteran overtrained for the bout. This time around, he's being more careful with properly timing his training sessions.