FIFA president Gianni Infantino says he will block any attempt to stage Girona and Barcelona's LaLiga match in the United States next year.
Both clubs have agreed in principle to the proposal to stage a game in Miami in January as part of a 15-year agreement between Spain's top division and Relevent Sports.
LaLiga president Javier Tebas has met with serious opposition since putting forward the proposal, with the Royal Spanish Football Federation (RFEF) and Association of Spanish Footballers (AFE) publicly against the plans.
Infantino has now added world football's governing body to the list of those who believe the match must not be staged outside Spain.
"FIFA will not authorise the playing of a match either in the United States or in any other location that isn't the stadium of Girona," Infantino said at a news conference.
"The FIFA Council has addressed the subject, and we stress that official matches of national leagues should be held in the country itself.
"As FIFA president, I announce that the organisation is against LaLiga's idea and will forbid Girona-Barca to be held in the United States or any other country that isn't Spain."