Before a recent workout at the Wild Card Gym, Manny Pacquiao boldly predicted a knockout victory when he gets in the ring with unbeaten welterweight champion Keith Thurman on Saturday night in Las Vegas.

The Filipino great has never been a big boaster, and he has only knocked out one of his last 15 opponents over the past decade — a shocking statistic for those who still think of Pacquiao as the world-beating force in his rampaging prime.

He won't say whether he's audaciously calling this KO out of true belief or pure promotional chutzpah. But Pacquiao has been speaking his mind more than ever in the late days of a 25-year pro career with no end in sight, and he keeps it up even while facing a fight that could immediately end his recent resurgence.

"I like the fight because it's a challenge for me, but I know I'm going to win," Pacquiao said.

Pacquiao insists he isn't thinking much about his political life while he trains in California, even if his stances already overshadow his abilities among a huge segment of the public. He speaks only about his fight with Thurman, the gifted welterweight determined to end Pacquiao's storied career.

"Just focus on discipline and work hard," Pacquiao said when asked the secret of his longevity in the ring. "Don't think about anything else but the training. Boxing is all about focusing and working hard. Nothing else. If you're thinking about anything except preparation and training and your workout, you'll forget about boxing. Boxing is about how you punish yourself."

Yet Pacquiao has bridged all sorts of apparent contradictions and overcome all manner of normally unsurpassable obstacles during a quarter-century in the professional ring.

A teenager who needed rocks in his pockets to make the 105-pound minimum weight for his professional debut in 1995 somehow grew up to become the only eight-division champion in boxing history. A 5-foot-6 slugger with an unremarkable frame tore through divisions stacked with larger champions, including Oscar De La Hoya, the bulky Miguel Cotto and even the 154-pound, 5-foot-11 Antonio Margarito.

The politician couldn't resist one last equivocation, followed by one more insight into his reasons for fighting on.

"Boxing is my passion," Pacquiao said. "I love to play basketball, but you are (on) a team. You don't know which people are shooting, you or your teammates. Boxing is you alone. When people are cheering for you, it is for you."