Ceferin has warned the four elite clubs which have not left the Super League project that they could be banned from the Champions League.
Despite eight of the 12 members announcing their departure, Real Madrid, Barcelona, Juventus and AC Milan have not aborted the idea of breaking away from UEFA and forming a new competition.
“It’s crystal clear that the clubs will have to decide if they are Super League or they are a European club,” Ceferin told the Associated Press.
“If they say we are a Super League, then they don’t play Champions League, of course
“And if they are ready to do that, they can play in their own competition.”
Meanwhile, UEFA’s Executive Committee decided on Friday against disqualifying Real Madrid from the Champions League this season, ahead of Los Blancos’ game with Chelsea in the semi-finals.
Ceferin also made it clear that the teams who left the Super League project could face no consequences compared to the aforementioned four.
“We still are waiting for legal expertise and then we will say, but everybody faces consequences for their decisions, and they know that,” added Ceferin.
“For me, it’s a very different situation between the clubs that admitted their mistake and said, ‘We will leave the project.’
“The others mainly know I would say that this project is dead, but they don’t want to believe it, probably.”
The UEFA president also claimed that he feels betrayed by the clubs who conceived the idea of creating a Super League.
“The worst day was Saturday, because then I realised that it was a pure betrayal, that some people lied to us for years,” Ceferin said.
“It was quite strange because I didn’t know what exactly will happen the next day. It was like something will be announced; nobody knows what.”