Andy Ruiz will look to become Mexico's first heavyweight champion after replacing Jarrell Miller as the opponent for unbeaten WBA, IBF, IBO and WBO titleholder Anthony Joshua.

Miller was withdrawn from the June 1 fight at Madison Square Garden after doping violations.

The 29-year-old Ruiz, who is based in California, gets his second shot at a world title, having lost on points to then-WBO champion Joseph Parker in December 2016.

That is his only loss in 33 professional fights. His last fight was 10 days ago, when he forced the fifth-round stoppage of Alexander Dimitrenko.

Joshua has a 22-0 record, with 21 knockouts. He hasn't fought since beating Alexander Povetkin at Wembley Stadium in September, and is boxing for the first time in the United States.

Eddie Hearn, who is promotes Joshua, says his boxer is taking the fight very seriously.

"I'm just glad that AJ and the people who know boxing, know what a difficult fight this is because when you look at the guy, you think it's going to be easy work for Anthony Joshua," Hearn told Sky Sports.

"A lot of people think this guy's not in Joshua's shape, he's not. But he's got a tremendous boxing IQ, fast hands, good work rate and he's not afraid to let his hands go. He's one of the reasons I wanted to choose him because I know him, I know what he's all about.

"Look at his response today, and look at the response from people in boxing - they say this is a much better fight than Jarrell Miller because he has much faster hands, he likes to move inside, he has a great amateur pedigree as well, and this is a massive banana skin.

"AJ doesn't really have a lot to gain, because the outsiders are saying 'he'll win that fight easy', but talk to people around here and you'll get the reaction from them today. They know this is a real, real, tough, tough fight.

"Andy Ruiz has a chance to make history and become the first-ever Mexican world heavyweight champion. Mexico is behind Ruiz and he believes he's going to do it. He really believes he'll beat Joshua."