By Keith Idec

Raul Rivas respects Vasyl Lomachenko, his father/trainer and everything they’ve accomplished thus far in his three-year pro career.

But Jason Sosa’s trainer/manager is convinced Sosa will give Lomachenko his toughest fight to date Saturday night. Based on what Rivas has seen in his ever-improving fighter, he is certain their HBO “World Championship Boxing” main event isn’t at all the complete mismatch it has been made out to be by most of the media and boxing fans.

Reverence for Lomachenko is at an all-time high following a seven-round domination of previously unbeaten Nicholas Walters in his last fight. The unique Ukrainian southpaw was so good that night, Walters quit on his stool before the eighth round began November 26 at The Cosmopolitan in Las Vegas.

There is zero chance, according to Rivas, that something similar will happen Saturday night at MGM National Harbor in Oxon Hill, Maryland.

“I promise you Lomachenko’s not just gonna dominate like he did with Nicholas Walters,” Rivas said during a press conference Thursday. “I know that with the social media, [they’re stating], ‘Oh, Jason had a draw [with Walters]. Lomachenko made him quit.’ Styles make fights and I will promise you that Lomachenko will have his toughest fight Saturday. Because this young man [Sosa], he’s relentless, and his heart and determination, and every fight he gets better.

“And I know that the media [says], ‘Well, two gold medals, 396 [amateur] fights, one loss. Three amateur fights. Turned pro at the age of 21. He has no chance.’ That’s OK. We love to be the underdog. But we definitely want the challenge. When [promoter] Russell [Peltz] called me, he said, ‘Listen, Chino, I spoke with Top Rank. Are you interested in fighting Lomachenko? Yes.’ No hesitation. Yes, because as a trainer, I see flaws as well. So if my fighter stays mentally focused and we execute a game plan, it’s gonna be a fight that’s very entertaining to the public and the media. I promise you that.”

The 29-year-old Lomachenko (7-1, 5 KOs) is a 25-1 favorite over Sosa (20-1-4, 15 KOs), a late-blooming former WBA world super featherweight title-holder. Lomachenko, a two-time Olympic gold medalist, has won six straight fights since suffering his lone professional defeat – a split decision to Mexico’s Orlando Salido (43-13-4, 30 KOs, 1 NC) in a 12-rounder three years ago in San Antonio.

The 130-pound champion has been especially impressive in his past two fights, a pair of relatively easy victories over Jamaica’s Walters (26-1-1, 21 KOs) and Puerto Rico’s Rocky Martinez (29-3-3, 17 KOs). Lomachenko won the WBO world super featherweight title by knocking out Martinez in the fifth round June 11 in The Theater at Madison Square Garden and made his first defense against Walters.

Rivas believes Sosa is so much stronger mentally than Walters and Martinez, that it’ll help the rugged brawler compensate for the skill differential between him and Lomachenko.

“My favorite fighter is Hagler, of all time,” Rivas said. “Reason being is that his heart and will and determination would break fighters. No disrespect to Lomachenko, I believe that the fighters that he’s been matched [against], other than Gary Russell, have been fighters that Jason Sosa would’ve knocked out maybe in between four to six rounds. That’s including Salido, which he lost to. We’ve been trying to fight Salido and that fight has never been able to be matched.

“We wanna fight the best. [Lomachenko is] an amazing fighter. I have a lot of respect for him and his father, who’ve done an incredible job. And I honestly, from the bottom of my heart, respect that man with all of my heart because I’m a trainer, and I know how difficult it is to build what his father has done with this young man, as I’ve done with mines.”

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