Real Madrid coach Julen Lopetegui spoke to the press on Friday ahead of Saturday's La Liga trip to take on Athletic Bilbao at San Mames.
The former Spain boss was asked about the idea of taking league games to the USA, with Barcelona and Girona's match at Montilivi in January expected to be moved to Miami.
Lopetegui said he was not "comfortable" with the idea and suggested it goes against the competitive balance of league football.
"I'm not in favour of what is happening," he said. "It doesn't make the league equal. Every team should play at the same grounds."
Barça coach Ernesto Valverde, meanwhile, was asked if playing Girona in Miami would be easier than playing them at Montilivi, where Madrid lost last season but Barça won.
"I have no idea because we’ve never played Girona in Miami," he said. "I can tell you after, if it goes ahead. I can only say that it was tough to win (at Montilivi) last year."