Julian Williams senses those that are apathetic toward his upcoming fight largely are unfamiliar with Jeison Rosario.

The Dominican Republic’s Rosario isn’t a prominent junior middleweight. Williams knows Rosario well, though, enough to believe he isn’t in for an easy night January 18 in Philadelphia.

“I think he’s a tough fighter and I think a lot of people are overlooking him because they don’t know his name,” Williams told BoxingScene.com after a press conference Tuesday in Philadelphia. “Just because you don’t know him, that don’t mean he can’t fight. I think he’s coming to win, which his gonna make for an exciting fight. Once that bell rings, man, anything’s possible. So, I just can’t expect that he’s gonna come and lay down, just because I’ve got these titles and just because he’s in my hometown. You know what I mean? So, I’ve gotta be fully prepared for this guy.”

Philadelphia’s Williams, 29, will make the first defenses against Rosario of the IBF, IBO and WBA 154-pound championships he won when he upset Jarrett Hurd nearly seven months ago. Hurd (23-1, 16 KOs) was a 6-1 favorite that night, but Williams (27-1-1, 16 KOs, 1 NC) knocked him down during the second round, took Hurd’s hardest punches and out-boxed the former champion en route to winning a 12-round unanimous decision at EagleBank Arena in Fairfax, Virginia.

The 24-year-old Rosario (19-1-1, 13 KOs) most recently edged Mexico’s Jorge Cota (29-4, 26 KOs) by split decision in a 10-rounder April 20 at Dignity Health Sports Park in Carson, California.

Rosario’s sole professional loss came against Nathaniel Gallimore, who stopped Rosario in the sixth round of their April 2017 battle at Sam’s Town Hotel & Gambling Hall in Las Vegas. Williams beat Gallimore (21-4-1, 17 KOs) by majority decision in a 12-rounder in April 2018 at Hard Rock Hotel & Casino in Las Vegas.

“I’ve been watching Jeison Rosario for the past two years,” Williams said. “Because you’ve gotta remember, we’ve got a common opponent. We’ve got Nathaniel Gallimore. And when I was getting ready for Gallimore, that was one of the fights I was studying. And then every time he fought after that, I paid attention to him because it was a familiar name and a familiar face. I’ve seen the Mark Anthony Hernandez fight. I’ve seen the Jamontay Clark fight. I didn’t see the fight with Cota. But like I said, I’m very familiar with Jeison Rosario. He’s a decent fighter and I’m pretty sure he’s gonna come prepared.”

FOX will televise Williams-Rosario as the main event of a primetime telecast January 18 from Temple University’s Liacouras Center.

Keith Idec is a senior writer/columnist for BoxingScene.com. He can be reached on Twitter @Idecboxing.