KSI has rejected Jake Paul's offer to fill in for Alex Wassabi in a boxing bout later this month.
Wassabi is thought to have been forced to pull out of his fight with KSI due to injury.
Paul then took to social media to offer himself as a replacement, having seen his own clash with Hasim Rahman Jr cancelled.
The American is a long-time rival of the Englishman and appeared to suggest that he was willing to fight KSI for free. “My manager just told me KSI is down but only if I fight him for free and he keeps all the revenue. That’s what they offering… I said hurry the f*** up and send me the contract,” Paul tweeted.
But KSI has now rejected Paul's offer out of hand, firing a shot at the American for not honouring his word.
The YouTuber tweeted out his rejection, as he insisted the fight scheduled for 27 August would go ahead as planned.
"I will honour my word to my fans and to my opponent because my word means something unlike yours. The show will go on on August 27th and you or MVP won’t have a thing to do with it. Enjoy your night out buddy @jakepaul," KSI said.
The news comes after Paul had called out KSI and offered to fly to London to take on the English YouTuber. He set out his terms for a deal on Twitter.
"Heard that Alex is out bc of a concussion. F***** up. This was a big opportunity for Alex. He will be back. KSI… everything happens for a reason. I’ll come fight in your hometown. Your boxing company. You are A-Side. I also agree to make 180 pounds for August 27. You accept?" Paul tweeted.
Alongside that message, Paul also posted a video, in which he further backed up his offer. The American also fired a subtle hint that KSI would attempt to turn him down.
"KSI's fight man, I heard the news, it sucks for Alex obviously. He has a concussion, he can't fight. But now this puts KSI into a corner, if he doesn't accept the fight with me, we all just know that he's scared. KSI I will come to London, I will weigh 180 pounds for the fight, you can be the A-side, what's your excuse? Do you accept?" Paul said.
KSI has never take on the younger Paul brother in the ring, though he has fought Logan Paul twice before. The first was in a white collar bout, which ended in a draw, before he won the rematch via a split decision.
That rematch was KSI's last outing in the ring, with the fight with Wassabi having been set to be his first since he defeated Paul. The younger Paul brother has fought five times at a professional level, winning all of them, with four of those victories coming via a knockout.
