Derik Santos Rosario is very familiar with WBO light heavyweight champion Sergey Kovalev.
Rosario was the assistant coach of Kovalev's former head trainer John David Jackson.
Jackson and Rosario trained Kovalev for years. Following Kovalev's back to back defeats to Andre Ward, there was bad falling out with Jackson. Kovalev is now being trained by former world champion Buddy McGirt.
This Saturday night, Kovalev will defend his world title against Mexican superstar Saul "Canelo" Alvarez at the MGM Grand in Las Vegas.
Canelo is moving up by two weight divisions to challenge Kovalev for his title.
“Kovalev still has a good punch, he always had a lot of power, but Canelo's speed, his ability to throw combinations to the body and the movement will give Kovalev a lot of problems. If Canelo manages to get to the body, he will beat him in that way," Rosario told George Ebro.
“Kovalev is very dangerous and from outside or at medium distance Canelo will not be able to deal with the Russian. Maybe [Kovalev's] current coach who is good, Buddy McGirt, is working on that, but the truth is that Kovalev never wanted on the work inside. He never wanted to learn that part of boxing.
“As much as I tried to show him and tell him [to fight on the inside], he said no, that it was not his style. He never wanted to learn it. When we brought someone to press him, he didn't know how to defend himself on inside, but he pushed to stay away. It was his fault. He never wanted to do it. He won everything with his punch, with the long distance. Knockout after knockout, he thought in his head that he didn't need anything else. I wanted to explain, but he couldn't be bothered. And as he won, I couldn't make him change.
“Canelo works so well to the body. Canelo and his team chose Kovalev, because they know all this, his style. They were not going to take a fight against Beterbiev, nor Bivol. Just as they chose Rocky Fielding over Callum Smith, so they chose Kovalev. And I don't blame them. I would have done the same."
