Shawn Porter won the IBF's welterweight title in his 24th fight in December, but his father and trainer, Kenny Porter, has him thinking he's only fought once.

While Porter prepares for his first defense against former beltholder Paulie Malignaggi on April 19 at The D.C. Armory in Washington, D.C., the 26-year-old Ohioan will envision an opponent who is larger than any heavyweight the sport has ever seen.

"I've already told Shawn that he's now 1-0 as a fighter. That's how we're approaching it. He's won one fight, and that's it," Kenny Porter told RingTV.com.

"This guy that we're getting ready to fight, in our minds, and the way that we're approaching it, he's 6-foot-6 and he weighs a thousand pounds. We're going to come at him, having already trained harder than we have going into our last fight. We've been training already for 60 days as of yesterday."

Promoted by Golden Boy, Porter (23-0-1, 14 knockouts) will meet Malignaggi (33-5, 7 KOs) as the second fight featured on a Showtime-televised card headlined by a 175-pound IBF/WBA unification bout between Bernard Hopkins and Beibut Shumenov that will also include Peter Quillin's third defense of his WBO middleweight title against Lukas Konecny.

Porter is coming off a unanimous decision that dethroned southpaw Devon Alexander during which he dictated a physical fight that left both men bleeding from cuts above their eyes.

Porter ended Alexander’s winning streak at four consecutive bouts since falling to Tim Bradley, the current WBO 147-pound beltholder.

"We'll be using our jab from the outside like we did against Devon Alexander," said Shawn Porter. "But, obviously, Malignaggi's got lots of knowledge and he's ring savvy, so he knows how to move around the ring."

A former junior middleweight who is managed and trained by his father, Kenny, Porter’s win over Alexander followed last September’s unanimous decision over ex-beltholder Julio Diaz that made up for the draw they had in December 2012.

Meanwhile, Malignaggi, 33, rose from a second-round knockdown in his last fight to score a unanimous decision over ex-beltholder Zab Judah.

In victory over Judah, Malignaggi retored is his “Magic Man” nickname by rebounding from a split-decision loss last June to Adrien Broner, who dethroned Malignaggi as WBA 147-pound beltholder. Malignaggi's loss to Broner was his first loss since falling by 11th-round knockout to Amir Khan as a junior welterweight at Madison Square Garden in May of 2010.

"We expect Malignaggi not to fight us like he fought Broner, where he tried to kind of stand toe-to-toe with Broner and exchange. I don't see him trying to do that us, and neither does my dad," said Shawn Porter.

"We expect him to try to use his reach and his speed and some movement a little bit more. But we've got some fast guys in here, and we're going to work on cutting off the ring and getting to his body and slowing him down, and making this a great, exciting fight."