But Ceferin also told Britain's Mail on Sunday that the six English clubs – Chelsea, Manchester City, Arsenal, Tottenham Hotspur, Liverpool and Manchester United – deserve greater leniency as they were the first to back out.
He said their stance were in contrast to those of Real Madrid, Barcelona and Juventus, ridiculed by Ceferin as "the ones who feel that Earth is flat and ... think the Super League still exists."
In the space of 48 hours beginning last Sunday, UEFA, aided by fans and politicians, quelled a mutiny by English, Spanish and Italian clubs attempting to form a quasi-closed tournament designed to supplant the existing UEFA Champions League.
Nine clubs, including the so-called 'Big Six' in England, subsequently withdrew.
But Ceferin, who thanked British Prime Minister Boris Johnson for his opposition to the Super League, said disciplinary action remained an option for UEFA, European football's governing body.
"Everyone has to take consequences for what they did and we cannot pretend nothing happened," he warned.
However, the Slovenian lawyer, elected UEFA president in 2016, added: "But for me it's a clear difference between the English clubs and the other six. They pulled out first, they admitted they made a mistake. You have to have some greatness to say, 'I was wrong'."
"But everyone will be held responsible. In what way, we will see," he said.
The irony is that UEFA was on the brink of enacting changes that would have entrenched the position of many of the established UEFA Champions League powers behind the Super League.
But Ceferin said he was open to dropping the two extra UEFA Champions League spots in an expanded competition that was meant to be reserved for clubs based on their historic records.