Last year, La Liga said it wanted to hold Barcelona’s meeting with Atletico Madrid in Miami, before dropping the idea because of time constraints.
Real, who have won a record 36 La Liga titles, said Villarreal playing their home fixture away from their own stadium would be “altering the competitive balance and granting an undue sporting advantage to the applicant clubs”.
Barca are scheduled to face Villarreal at the Nou Camp on 1 March, 2026.
“The integrity of the competition requires that all matches be held under the same conditions for all teams,” added Real in their statement.
“Unilaterally modifying this regime breaks the equality between contenders, compromises the legitimacy of the results and sets an unacceptable precedent that opens the door to exceptions based on interests other than strictly sporting, with a clear impact on sporting integrity and the risk of adulteration of the competition.”
The club said it had asked Fifa not to authorise the staging of the game without the prior consent of all La Liga clubs, and asked Uefa to urge the RFEF to withdraw the request.
Other one-off matches, such as the Italian Super Cup and Spanish Super Cup, have been held abroad in recent years.
With the San Siro hosting the opening ceremony of the Winter Olympics in February, AC Milan are hoping to play their Serie A match against Como in Perth, Australia, as the two events clash.
The plans, however, have yet to receive approval from Fifa, Uefa, Football Australia and the Asian Football Confederation (AFC).
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