Pep Guardiola expressed his disagreement with the idea of a breakaway competition for Europe's top clubs, saying a prospective Super League would "kill" domestic football.
Reports suggesting Bayern Munich and their chairman Karl-Heinz Rummenigge might attempt to lead the creation of a new competition for Europe's biggest clubs have been circulating since late 2018, and Guardiola is one of many to have voiced their concern.
Bayern and Rummenigge have strongly denied the reports but rumours persist that the clubs who dominate their respective leagues might seek to establish a year-round competition that offers the quality, competitiveness and lucrative rewards of the Champions League.
Guardiola was asked for his views on a breakaway league in an interview with Catalan daily newspaper Ara, and he said: "I do not agree much with the idea. Someone should explain to me [why it's a good idea].
"If it happens we'll kill the leagues. If Barca and Madrid go and they do not play against Espanyol, who will follow the league? The Spanish league will die.
"In England they are very intelligent, the grounds of the fourth division are full. England will not let this essence of local football die."
Guardiola's failure to deliver glory in the Champions League has been one of his few shortcomings during an otherwise hugely successful three-year spell at Manchester City.
City have been knocked out in the round of 16 once and the quarter-finals twice under Guardiola, but he expressed his appreciation for the Champions League's format while making it clear he does not see an alternative European competition as the way forward for anyone.
"Part of the greatness of the Champions League is that it is not every Sunday," said Guardiola. "If games were every week it would lose its charm.
"Barcelona v Espanyol is very necessary for the city. And the more Catalan teams in La Liga, the better.
"If we kill the domestic leagues, nobody will be interested in watching teams that do not have the chance to go to the European league."
Guardiola’s record in domestic leagues is very strong.
His City side have won back-to-back Premier League titles in England.
While he was manager at Bayern in the Bundesliga he secured three consecutive championships between 2014-16, mirroring his achievements with Barca in the Primera Division in 2009-11.