Lucas Matthysse has vowed to fight "to the death" in his July title defence against Manny Pacquiao, describing the Philippine boxing legend a diminished star.
But the 35-year-old Argentine -- who took the vacant World Boxing Association welterweight title in January -- said it was still a "dream-come-true" and "an honour" to face Pacquiao, winner of eight unprecedented world titles in different weight classes.
"Obviously he is still a very great fighter but since the knockout of Marquez, I think he is not the same fighter anymore," Matthysse said at a joint news conference in Manila, referring to the Filipino's sensational 2012 knockout loss to Juan Manuel Marquez.
"He is not in his prime anymore," the Argentine fighter added.
Pacquiao, 39, will fight Matthysse for the WBA "regular" welterweight belt on July 14 in Malaysia's capital Kuala Lumpur.
The Filipino has 59 wins with 38 knockouts in his career, and is currently a senator in the Philippine parliament.
Many in the country believe he will one day run for president, but Pacquiao has insisted that he is happier in the ring than in politics.
But Matthysse -- who has 39 wins with 36 knockouts in 43 matches -- said he was not fazed by the status of his opponent.
"Sure, Manny has won so many titles... I (have) only won one title. I am not going to give it up. I will die for it if I have to," Matthysse said. "I will defend this title to the death."
Pacquiao has not fought since he lost his World Boxing Organization welterweight crown in a shock points defeat to Australia's Jeff Horn last year, and has not knocked out an opponent in nearly nine years.
He insisted, however, that he was far from finished.
The Kuala Lumpur bout will likely mark the first time in 15 years that Pacquiao will be fighting without his long-standing trainer Freddie Roach, who expressed hurt last week after saying ties have been cut.
The boxer suggested Wednesday that role might go to his own friend and compatriot Buboy Fernandez, at least for the Matthysse bout.
"We just want to try and experience that Buboy will handle this one fight and after that go back to Freddie," Pacquiao said, stressing he had yet to decide and was "not closing the door" on Roach.
The bout will also mark Pacquiao's first venture as a promoter, instead of having his long-time American promoter, Bob Arum of Top Rank, handle that end of the business.
"Bob Arum is in charge of American pay-per-view and that's it," Pacquiao told AFP.