Spence Jr and Pacquiao will clash in a welterweight unification bout on August 9 in Las Vegas, Nevada.
Spence Jr, 27-0 (21 KOs), is a 31-year-old American who has stopped all but six of his opponents to date.
He claimed the IBF welterweight title from Kell Brook in 2017 and subsequently made two brutal defences as he comfortably outclassed Lamont Peterson and Carlos Ocampo.
Now, Spence Jr plans to cement his place at the top of the pound-for-pound list by unifying the welterweight division, but must first defend his WBC and IBF 147-pound titles against Pacquiao.
Asked what he will do to the man who stands in the way of his unification plans, Spence Jr replied to Showtime's Brian Custer via RingNews24: “I think he’ll definitely retire after this fight.
“I don’t know [if I’ll stop him], we’ll see. You’ll have to tune in and order.”
Spence Jr also spoke about his long-standing rivalry with Terence Crawford and says he has not given up hope of fighting his fellow American.
“I definitely want that fight, and we’ve just got to make it happen," Spence Jr added. “It’s for his guys and my guys to talk to each other and see if it can happen.
"If it can’t happen, I’ve got to move up.”
Pacquiao, one of the Philippines' most popular sportsmen, is confident he has the weapons to dethrone Spence Jr.
The 42-year-old, who trains at the Wild Card Boxing Club in Los Angeles, has not fought since he beat Keith Thurman in July 2019.
However, he insists the two-year long layoff won't affect him in the slightest.
“I started boxing since I was 12 years old and until now, so it’s good for me that I have a layoff for two years.
"So, when I get back to training, I feel like hungry to focus on and dedicated to my training and make sure that I’m 100-percent conditioned, and that’s my drive.”News Now - Sport News