If Andy Ruiz Jr hoped Anthony Joshua might be a broken man after he relieved him of his collection world heavyweight title belts in June, he has got another thing coming.

Joshua met the media for the first time since he began training for his December 7 rematch with Ruiz on Wednesday and left no one in any doubt that he believes he is ready for revenge.

“We haven’t done anything differently mentally, I am a champion,” Joshua said. “I walked into the gym and three years later I was Olympic champion. I have had one loss but I am not about to become a p-ssy overnight and not be able to fight.

“I can fight, that is it. I don't need to reflect on that, I just need to win.”

Wednesday was media open day for Joshua at his gym at the English Institute of Sport in Sheffield. But Joshua was in no mood to give any sight of what he has been working on, as he just gave interviews to a select group of journalists and decided not to allow anyone to watch him train.

It is nearly six months since Joshua was stopped in seven rounds by Ruiz at Madison Square Garden, losing his WBA, WBO and IBF heavyweight titles in the process. The rematch takes place in a purpose-built arena on the outskirts of the Saudi Arabian capital, Riyadh.

Joshua, who turned 30 last month, shrugged off suggestions from British rival Tyson Fury that he had not been ready to get in the ring with Ruiz, saying that Fury has never had to deal with the pressure Joshua had.

“Tyson is at a different stage in his career,” Joshua said. “I always say he’s turned pro the year I had my first fight and he’s been pro 11 years doing his thing.

“He would never understand what I’m going through. That's another entitled opinion, I was ready, I was in a good place.”

While Ruiz has been claiming in social media posts that he has lost weight, Joshua says he has not trimmed down ahead of the rematch.

“I think it is more to do with the angles of the photos,” he said at suggestions that he has looked less muscled. “I am still as strong as ever, still as heavy as ever.

“Weight is a big factor in the heavyweight division these days but I don’t think it should be such a big deal. I am not really focused on my weight, I am just focused on my sparring.

“I could weigh anything but it just comes down to how I perform in the ring. I am not interested in getting down or up to 110kg and then thinking I am fit. “If I am sparring 10 or 15 rounds at 120kg them I am good. The sparring gives me all the information I need.”

Rob McCracken, his trainer, has shared some of the padwork for this fight, but he says the sparring partners brought in to help Joshua prepare have given the former champion a particularly hard time.

“Since Josh has been a professional sparring partners have always come here to try to rip his head off and make a name for themselves,” McCracken said. “This group of sparring partners has done really well and pushed him every step of the way.”

Despite losing to him once, Joshua remains resolutely unimpressed by Ruiz, writing off claims about his speed and ability as good promotion.

“They think he’s so great,” Joshua said. “So when I beat him I want everybody to bow to my feet and tell me how great I am."