UEFA's chief of football Zvonimir Boban said those in the game must fight FIFA's proposal to stage the World Cup every two years because if it succeeds it would "hurt everybody."
FIFA held an online summit last month to discuss moving World Cups from occurring every four years to every two, which has already been met by strong opposition within UEFA.
Former Milan and Croatia star Boban said the idea was "even worse than the Super League," which was foiled earlier this year by wide-ranging public backlash from fans and European clubs.
"Every normal person who understand and respect football, cannot accept the biennial World Cup idea," Boban said via Gazzetta dello Sport. "You would cancel 100 years of history of the World Cup, the best competition in the world.
"Football cannot be revolutionised unilaterally without a good consultation with all the parts involved and ordering other institutions to do other things: UEFA must organise Euro every two years, domestic league must cut the number of teams, this and that.
"The most absurd thing, even if probably clubs don’t realise it yet, is the two windows for international breaks. Three games in a row and a player is dead. Two games you can recover, three not. Travels don’t hurt footballers, too many games in a row do."
UEFA chief of football Zvonimir Boban says a biennial World Cup would be "even worse than the Super League".
While several UEFA officials have spoken out against the plan, Boban's opposition is notable given his ties to FIFA president Gianni Infantino.
Boban worked as FIFA's Deputy Secretary-General from 2016 to 2019.
"It is such an absurdity that I could never imagine that could come from a president I still love after working with him for three years or from a football person like [Arsene] Wenger," he said. "This is idea is so crazy that we really have to fight against it because it would hurt everybody."
Boban said UEFA would never propose holding the Euros every two years, "even if it meant more money".
"It would be bad for players, leagues, clubs as well as for the appeal of competitions," he added. "It does not respect anybody. It would destroy football's institutions together with the footballing pyramid that was built thanks to decades of work."
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