Tyson Fury has emerged as a surprising new challenger to Deontay Wilder after failed talks with Anthony Joshua has left the American frustrated. Now a former sparring partner of both men, UFC heavyweight Walt Harris, has given his opinion on the two fighters ahead of their possible match-up in December.

WBC heavyweight title-holder Wilder has been scheduled to go up against Anthony Joshua next April, however, talks between the two teams have repeatedly stalled and now appear to have reached breaking point.

Into the breach stepped Tyson Fury and the motormouth Mancunian has been in typical bullish form, accusing Joshua of lacking the bottle to take on Wilder. Fury has now revealed that his own talks with Wilder's team are progressing well, telling Sky Sports that the deal is "99% done".

Before the potential match-up in December, Fury will face two-time heavyweight title challenger Francesco Pianeta on August 18 but the 33-year-old Italian is unlikely to put up much resistance.

The 6ft 5ins powerhouse Walt Harris has been with Team Fury in preparation for the fight against Pianeta on the undercard of Carl Frampton’s sell-out date at Windsor Park in August.

The 35-year-old mixed martial arts star has also previously spent time in camp with countryman Wilder and has now compared his time in the ring with the two men.

“They both present different problems. Deontay’s power is world class, it’s unlike anything I’ve ever felt," he told iFL TV.

“He is athletic as well but he doesn’t move and keep up the intensity and the pace that Tyson keeps up. For a 6ft 9ins, 270lb guy to move and throw as any punches as he does, it is unseen.

"I’ve never seen it. I think they both have their skill-sets but I think Tyson is the better boxer. His IQ for the game and what he does in the ring is just... I’ve never seen anything like it.

“Deontay has more power but Tyson has cumulative power. He can throw four, five punches with power. D throws one, two – and you might not make it back from the one, two but Tyson puts them together and it is special.

“Tyson’s movement is a lot better. The way he cuts angles and slips… I can’t hit him. We’ve probably done about 35 or 40 rounds – I’ve hit him on the face about seven times.

“He is slick. The slickest guy I’ve ever been in there with.”

That certainly bodes well for Fury if what Harris says is true.

Until Fury gets in the ring with a truly recognised and respected opponent, question marks over whether he can return to the form that saw him beat Wladimir Klitschko will remain.