The European Super League crumbled on Wednesday with 10 of the 12 founding clubs turning their backs on the three-day old project despite mastermind Florentino Perez insisting the widely-condemned breakaway tournament was not dead, but merely "on stand-by".
Perez shrugged off the withdrawals of the six English clubs as well as Inter and AC Milan, and Atletico Madrid.
Juventus said the project was unworkable.
"The project is on stand-by. The project exists, but half of them have left, tired of what they have heard over 24 hours, saying they don't want to continue," Real Madrid president Perez told Spanish radio station Cadena Ser.
When asked if it was wrong to think the breakaway competition was now dead, he added: "Absolutely".
Barcelona have yet to make their plans clear but they are "thinking about it", added Perez.
"UEFA made it look like we dropped an atomic bomb."
Of the campaign by fans, politicians and leagues and federations, he added: "It seemed orchestrated. It was like we had killed football. We were working on how to save football."
The withdrawals by Manchester City, Manchester United, Liverpool, Arsenal, Chelsea and Tottenham had come just 48 hours after the league's unveiling late on Sunday, following a furious response from fans and officials.
"We got it wrong," said Manchester United co-chairman Joel Glazer.
"This is the world's greatest football club and we apologise unreservedly for the unrest caused during these past few days."
Glazer's apology followed an earlier similar act of contrition by Liverpool owner John W Henry.
The American also apologised and added: "It goes without saying but should be said, the project put forward was never going to stand without the support of the fans."
Manchester City chief executive Ferran Soriano admitted his club made a "mistake" to get involved.
However, the climbdowns may not save the 12 clubs from punishment.
Karl-Erik Nilsson, who is also the president of the Swedish Football Association, said European governing body UEFA's executive committee would decide whether to take action against the clubs at its next meeting on Friday.
- Cash injection -
The Super League promised guaranteed entry for its founding clubs and billions of dollars in payments.
Many of the clubs have huge debts and wage bills, and suffered a sharp drop in revenues during the coronavirus pandemic.
But the project was vehemently opposed across the football spectrum, from fans to players, coaches, politicians, UEFA and FIFA.
The clubs were threatened with a ban from domestic and European football, while their players could even have been barred from representing their countries.
UEFA president Aleksander Ceferin had struck a conciliatory tone on Wednesday, saying he wanted to "rebuild the unity" of European football, and described the English clubs as "back in the fold".
"I said yesterday that it is admirable to admit a mistake and these clubs made a big mistake," Ceferin said in a statement.
"The important thing now is that we move on, rebuild the unity that the game enjoyed before this and move forward together."
Shares in Juventus plunged by more than 13 percent on Wednesday following a slump in the value of Manchester United stocks on Tuesday.
- 'Reconsider steps' -
In response to the English pull-outs, the Super League had said it was looking for ways to "reshape", insisting the "status quo of European football needs to change".
"We shall reconsider the most appropriate steps to reshape the project," its statement said.
British Prime Minister Boris Johnson hailed the English pull-outs, telling parliament: "The announcement was the right result for football fans, for clubs and for communities across the country."
Reigning European champions Bayern Munich and French giants Paris Saint-Germain had both come out strongly opposed to the breakaway league, dealing it a heavy blow.
On Wednesday, PSG president Nasser Al-Khelaifi was named as the new head of the European Club Association (ECA), replacing Andrea Agnelli, one of the key figures in the doomed Super League project.
Adding to the drama on Tuesday, Manchester United announced that executive vice-chairman Ed Woodward would step down from his role at the end of 2021.
Several players at the English clubs had voiced opposition to the Super League, and Manchester City manager Pep Guardiola commented: "It's not a sport when success is already guaranteed."