Dillian Whyte has fuelled his heated rivalry with Andy Ruiz Jr by taking aim at his next opponent.

Ruiz Jr's shocking upset of Anthony Joshua at Madison Square Garden in New York is still fresh in the memory for many boxing fans.

The 29-year-old became the first heavyweight champion of Mexican descent when he knocked Joshua down twice in the seventh round to claim the WBA, WBO, IBF and IBO titles.

However, he lost the belts to the Brit six months later in their highly-anticipated rematch in Saudi Arabia, with many criticising him for his poor diet and lack of preparation. 

Ruiz will face Chris Arreola in a comeback fight at the start of May after a long layoff.

Whyte, who has a well-documented history with Ruiz Jr and his team, responded by launching a blistering attack on the former heavyweight champion, calling him 'fake' and 'garbage.' 

"A strategic comeback fight," Whyte said to Sky Sports. "It's a fight that's going to make him look good.

"Make him look like, 'Oh yeah, he's this and he's that,' but on paper it's not. If you run it on paper, it's not, because Chris Arreola is shot. Chris Arreola has been shot for a few years.

"If he was fighting Chris Arreola a few years ago, people would be like, 'No, that's a garbage fight.' Now it's the same, if not worse.

"It's a good strategic move from his team, him coming back and he'll bash Arreola. 'Andy Ruiz, yeah he's back, and he's motivated, and he looked so good.'

"Let's be honest, it's Chris Arreola he's fighting. Typical joke fight from the fake Mexican.

"If he wasn't motivated when he had the whole world at his feet…He had 80 per cent of the major titles, and he wasn't motivated. We'll have to wait and see."