Anthony Joshua believes fight fans are missing out as his heavyweight rivals all look to play 'Game of Thrones' rather than get into the ring with him.

Joshua is now set to face Andy Ruiz Jr in the defence of his WBA, IBF and WBO heavyweight titles on June 1 at Madison Square Garden, after original opponent Jarrell Miller reportedly failed multiple drug tests.

The likes of Luis Ortiz and Michael Hunter had been linked with taking on the London fighter.

However, a showdown with WBC holder Deontay Wilder and fellow British heavyweight champion Tyson Fury remain high on the wishlist of fight fans across the globe.

Joshua, though, believes all of the politics outside the ring from various promoters and broadcasters means making those contests appears to be a thankless task.

"We're playing the Game of Thrones but I don't know why and I don't know what's happening and it's the fans that are missing out," Joshua said, quoted in several national newspapers.

"It's just amazing what's happening in the history of the sport at the minute with so many dominant heavyweights.

"As simple as it seems — why don't the best fight the best? It's what's in the background. Everyone has their own vested interest of where they are going to push their fighter."

On the subject of face-to-face meetings to try to thrash out an agreement once and for all, Joshua said: "I just don't understand sitting down with them.

"What more we can make out of it because we have made lucrative offers to fight these guys.

"We made an offer to Fury, he didn't want the percentage fee, he wanted a flat fee. But when you work out what the percentage would have been, it would still have been a higher percentage in terms of the pot.

"We made an offer to Dillian, we made an offer to Ortiz and he took far less to fight Wilder.

"So I look at it and think, 'What difference is it going to make to these guys?' Are they just going to say they want more or is it not about the dough?

"I have what they want, the four belts (IBF, WBA, WBO and IBO). In Game of Thrones, what's going to happen if someone holds the most power? They rule the Seven Kingdoms.

"So imagine someone said, I'll give you 10 more troops than me? I'm giving these guys a lucrative offer to fight me, which they can invest into their training.

"And the people outside are looking at it and saying, 'This is your chance, take it'."

Ruiz Jr and promoter Eddie Hearn held a press conference in Las Vegas on Saturday as the 29-year-old set out his game plan to tackle Joshua next month.

He has won 32 of his 33 professional contests, suffering only a thin majority-points defeat to Joshua's former opponent Joseph Parker during December 2016.

Ruiz Jr said: "This is a lifetime opportunity. It's my second chance to make history, to make my dreams come true. It couldn't happen any better than now. I just fought April 20. I'm sharp, I'm prepared. We don't have to start a new training camp, it just keeps going.

"I'm just really excited for June 1. Everybody is underestimating me in just the way that I look, but I have heart, I throw a lot of punches. I'm going to show the world what I am and what I can do. I'm going to prove everybody wrong. I'm going to bring those belts back to Mexico."

Hearn said when it came to picking a new opponent for Joshua, he wanted to make sure there would be a "real fight" on June 1.

"I'm a promoter but I'm also a fan. I didn't want to bring Anthony Joshua to Madison Square Garden to walk into a ring knowing we can't lose. Knowing it's going to go two rounds. Knowing it was an opponent coming for the money, not one who is trying to fight for his family, his legacy, for history.

"A couple of guys reached out to me that made me feel, you want it.

"But this man to my left (Ruiz Jr) was really the one that sent me those messages and I watched him in interviews and I thought, you know what? This guy really wants it."