Pacquiao and Marquez will fight for the third time on November 12, with Pacquiao defending his WBO welterweight championship at a 144-pound catchweight.
Pacquiao’s first fight at welterweight was against Oscar de la Hoya, whom Pacquiao defeated via technical knockout.
He has since fought and defeated Miguel Cotto, Joshua Clottey and Shane Mosley at welterweight.
The pound-for-pound king is giving Marquez credit, however, for being his toughest opponent at the 130- and 125-pound divisions.
Pacquiao and Marquez’ first meeting, which ended in a draw, was at the featherweight division, while their 2008 rematch was at super featherweight. Pacquiao defeated Marquez via a split decision in their 2nd meeting.
“I know that for this fight, he will train hard,” Pacquiao said of his opponent. “Marquez will give everything that he can for this fight. This is a different fight for him, this is the most important fight of his boxing career.”
But Pacquiao said he is also training hard, and has extra motivation for the trilogy bout as he wants to answer all the questions left by the first two fights.
Pacquiao is already in the Wild Card Gym in California, where he will finish his training camp for the Marquez fight.
