France head coach Didier Deschamps believes FIFA's proposed biennial World Cup plan will trivialise the tournament.
FIFA, led by chief of global football development Arsene Wenger, want to shift the World Cup format to see an edition take place every two years.
The former Arsenal manager's proposal would cause further scheduling issues for international footballers with an already heavy workload for club and country.
However, after both UEFA and CONMEBOL pushed back against the idea, Deschamps warned of devaluing football's showpiece event, though he appreciates any change will likely not come during his tenure with Les Bleus.
"To be honest, my first feeling in my playing career, being able to move on to a World Cup every two years, it makes me feel like I'm trivialising it," Deschamps told reporters on Thursday.
"That's the best word I can think of. I do not have all the ins and outs. I will not be the expert but until now, every four years, it was very good like that. We are used to it.
"Afterwards, it is according to the interests of each other. If the majority is there, it can pass. I think at that time, I wouldn't be concerned anymore. So I would watch."
Spain head coach Luis Enrique is also concerned about the problems it may force on footballers' workloads, though he accepts it would improve the overall experience for spectators.
"To unify a calendar and to have attractive possibilities for the viewer it is necessary in order for football to keep being attractive to young generations and to the world in general," he said.
"But it is obvious that the calendar needs to be reduced. I am not the right or capable person to advise from where it would need to be reduced.
"A World Cup every two years, as a national coach I would be delighted, of course. But a reduction is needed. And I don't know from where this reduction must come."