The IBF, WBA and WBO heavyweight champion makes the latest defense of his titles on the occasion of his US debut, when he fights his Mexican challenger at Madison Square Garden in New York, PA Sport reported.
Ruiz Jr., like Joshua aged 29, was only installed as Joshua’s challenger when Jarrell Miller’s six-month suspension ruled the champion’s first-choice opponent out.
The two fought at the same world championships in 2011, a year before Joshua excelled in winning Olympic gold, and narrowly missed each other again when Ruiz Jr. suffered his only professional defeat to Joseph Parker, who Joshua consequently ended up fighting instead.
Both Joshua and his challenger also took similar paths through life, their focus for boxing rescuing them from the troubled avenues they had been pursuing as teenagers, and the champion is therefore aware of the threat Ruiz Jr. poses when interest surrounds Joshua, Deontay Wilder and Tyson Fury and what is to come next.
“We were at the world championships in Baku in 2011,” Joshua said. “He knows a lot about me and I do him. He turned pro a year after when I started boxing so he has been around a long time and knows his craft. I know a lot about Ruiz.
“People speak about being fully focused on June 1. I am, but you can’t not look at the bigger picture. I’m sure he is doing it himself, you naturally look at the bigger picture. I don’t put blinkers on about seeing the potential (of fights with rival heavyweights Wilder and Fury).
“You had Wilder-(Dominic) Breazeale, you’ve got the Fury-(Tom) Schwarz fight after; you’ve got me in the middle. It’s all about what’s next.
“Even though it’s not the fight of the century or the mega fights, the possibilities keep me motivated.”
Joshua’s normally-reserved trainer Rob McCracken revealed he had felt his fighter needed a challenger of the caliber of Ruiz Jr .to ensure he remained motivated, and the challenger, who started boxing at the tender age of six, explained how like Joshua he once so very nearly lost his way.
“I was a little gangster when I was young,” he said.
“I had my head bald and hung around with the wrong kids. Boxing saved my life. There was something about it that made me want to go back and back. I was with the wrong people doing bad things.
“When my dad took me to Mexico and I joined the Mexican (amateur) team in Mexico City, that’s when it changed for me. I was 15 or 16 years old.
“Right now (Joshua) is looking past me and he should focus on this fight first. Anything can happen in this game; it takes one punch to change a fight.”