According to him, Joshua is “not good at boxing” and vowed to land another victory when they fight in a rematch.
The 29-year-old Mexican boxer pulled one of the biggest upsets in sport history to defeat Joshua on June 1.
The victory ensured Ruiz unified the IBF, WBA and WBO titles, but he is expected to face Joshua again later this year.
“The rematch is going to be the same. I am going to be more prepared and more ready,” Ruiz said, as quoted by the BBC.
“I know his flaws. I can do a lot better. The only thing that he can do is just run around, he’s not good at boxing.”
The Mexican added that he’s confident of beating Joshua again, having handed the Brit a first ever loss in his career.