Watch Jake Paul practice three-punch combo in training weeks before he used same move to KO ex-NBA star Nate Robinson

The clip, which featured footage of Paul rendering Robinson unconscious, included the accompanying caption: "Practice makes perfect."

Paul's post received a barrage of negative comments, most of which were from irritated boxing and MMA fans.

One tweet read: "Let’s be honest he’s probably the best YouTube boxer there is but put him up against a golden glove or even a bronze finisher and he’s getting sparked out.

"Even if he beats these MMA guys I still don’t think he’s proven himself as a boxer.

"Notice how he doesn’t call out any actual boxers, he knows he’s not there yet overall he’s not bad though I would say skill-wise a mid-level amateur."

Former UFC middleweight champion Michael Bisping - who recently hinted he's received an offer to box the younger Paul brother - also chimed in.

Britain's first UFC champion said: "Bags don’t hit back. Well, neither do basketballers for that matter."

Paul's brutal knockout of Robinson was his second as a professional boxer, the first of which came in January against fellow YouTuber AnEsonGib.

The former Disney actor has now set his sights on facing UFC superstar Conor McGregor, who he called out earlier this week in a foul-mouthed tirade on Instagram.

He said: "What the f**k is up you Irish c**t? Good morning Conor McGregor.

"I know you're probably beating up old dudes in a bar right now or maybe you're j**ing off as you're sick of f***ing your wife, I mean, she's a four [out of ten], Conor you could do a lot better, but happy Monday!

"My team sent you a $50 million offer this morning, $50 million cash, proof of funds, the biggest fight offer you've ever been offered.

"But you're scared to fight me Conor. You duck me as you're scared to fight a YouTuber.

"You're 0-1 as a boxer, I'm 2-0 as a boxer. I just came off the eighth biggest pay-per-view event in history.

"But you want to fight Dustin Poirier, who has less followers on Instagram than my f***ing dog, that's a fact.

"And Dana White, you're a f***ing p***y, you ugly f***ing bald bitch.

"You said there's zero per cent chance of this fight happening but there's zero per cent of you getting some p****.

"Conor, you're scared, Dana, you're scared. Sign the f***ing contract you idiots. Irish b***h, f** these guys."

McGregor - who is currently preparing for his UFC 257 rematch with Dustin Poirier - has yet to respond to Paul's call-outs or the expletive-laden message he received from him on Instagram.