Joshua (left) is out to regain the three heavyweight world title belts which were lost, along with his unbeaten record, when Ruiz knocked him down.
Klitschko was defeated by Joshua in 2017 at Wembley Stadium with a technical knockout and the two boxers have stayed in touch even after the Ukrainian retired later that year at the age of 41.
Anthony Joshua is set to earn a lot more than Andy Ruiz Jr in their highly-anticipated rematch on Saturday, December 7.
"I know "AJ" has been working on different technicals, he's slimmed down, so we've been working on different things and angles, different pressures and combos, ready for whatever he brings", Ruiz said.
Joshua, who lost his three world heavyweight titles to Ruiz on the 1st of June previous year says he has chose to "check" his approach after a first defeat.
Here at Legendz Gym, earlier than he heads to Saudi Arabia for a rematch with Joshua next Saturday, it is actual Ruiz alongside with his father, his lawyer (who has facilitated this interview) and his wise outmoded coach, Manny Robles, a individual who may perhaps perhaps perhaps fair no longer ever alternate.
"I don't know what he thinks, what's going on at the camp". We have to pressure, work the body, break him down.
He added: "This upcoming match is one of the biggest boxing fights in the world. The hard part is over, it's time to have fun on December 7". "I've got to show my skills, my talent".
The Mexican-American (33-1, 22 KOs) - whose sole career defeat came against Kiwi Joseph Parker back in 2016 - vowed to "prove everyone wrong" again as he displayed his lightning fast hands while smashing the pads at the public workout.
Joshua says he is confident he can be victorious and if he does he will tell everyone of how he went wrong.