The widespread public doubt about UFC superstar Conor McGregor's chances of beating Floyd Mayweather in their upcoming boxing bout has intensified after a video of the Irishman struggling in a sparring session with a boxer went viral.
South African professional fighter Chris van Heerden released some damning footage via social media of himself in the ring with McGregor in which he appears to land punches almost at will on the hapless-looking loud-mouthed martial artist.
The caption reads "People telling me Mayweather will have his hands full trying to land on McGregor – STOP IT! I respect McGregor BUT I ain't Floyd and I landed".
A former IBO welterweight champion with a professional record of 25 wins and two losses, Van Heerden has come under plenty of fire since posting the 2016-recorded video, but insists he's simply "standing up" for the integrity of his beloved sport.
"There's guys in the sport like myself that have devoted 10 to 15 years, trying so hard every damn day to make it to a position to fight for an opportunity like Conor has now," Van Heerden told Sunday Sport on RadioLIVE.
"He walks in and he just makes it sound like he can just walk out of a UFC ring and into a boxing ring and beat the best pound-for-pound boxer of this era, and that makes me angry."
"The reason I released the footage is to show people that he's not super-human."
However it appears there's also a significant amount of retribution involved in his motivations after claiming he'd been "ripped off" by McGregor's camp.
"I want to make it clear to the people that I'm not his sparring partner and I'm not part of his team. He approached me and he didn’t pay me one damn dollar.
He claims McGregor's team had cameramen there who filmed their sparring session and then, unbeknown to him, went about editing the footage in a manner which was unflattering and skewed the actual events in the UFC star's favour.
"I got angry and I said listen here, nobody's even asked me permission.
"You didn't pay me one damn dollar. I helped you out of the goodness of my heart, and you do this.
"If you're going to put anything out there put the real damn stuff out there and let people judge for themselves."
The 29-year-old went on to offer a scathing prediction of how he sees the fight playing out on August 26th, adding an unflattering assessment of McGregor's skills in the ring.
"It's going to be a TKO. Conor McGregor is going to take such punishment.
"His footwork is all over the place, his hands are down. He puts his chin out there for you to tag him.
"I think he'll come out and try to show people he's got skill in boxing and try to box with Floyd [Mayweather]….and Floyd's going to tag him whenever he wants to, make him miss at will.
"I'll tell you this right now, the moment Floyd starts tagging Conor – whatever he learnt in boxing, he's going to forget it. His body's going to act into instinct and he's going start doing his MMA style – hands down and cocky, and Floyd's going to continue to tag him.
"[Mayweather] is going to go into that defensive shoulder stance and start walking him down and beating him up, and the ref's going to stop it."
As for his own prospects, Van Heerden believes he's deserving of a spot on the Mayweather Promotions-run undercard, calling out current WBA 'regular' welterweight champion Lamont Peterson.
"Get me on that undercard, get me Lamont Peterson, accept my challenge and let's do it."