Real Madrid issued a sharply worded statement criticising Spain's soccer federation (RFEF) on Wednesday for what the club called a lack of respect and objectivity over an article mentioning coach Jose Mourinho.
The club were responding to a piece on the RFEF website saying Real's game at Atletico on Thursday would be "under the close scrutiny of Mourinho, who feels he has been mistreated by officials in recent league matches".
Real used an official statement to express indignation at the wording, which was not present in the latest version of the article on Wednesday.
"We consider it enormously serious that these remarks about our coach were made on the Federation's own website," Real said.
"They clearly demonstrate a prejudice that is a long way from the objectivity, neutrality and balance which should inform the organisation's offical publications.
"We demand action is taken for what we believe is a lack of respect and consideration to the coach of our team, the club itself and the fans."
Real won the first leg of the King's Cup quarter-final tie against Atletico 3-1.
RFEF officials were not immediately avaialble for comment.
Mourinho, renowned as an outspoken figure, was banned for two matches earlier this season for verbally abusing a referee.
At a news conference on Wednesday, the Portuguese repeated his view that Real had been denied what he felt were two clear penalties in Sunday's 1-1 draw at Almeria that left his side four points adrift of La Liga leaders Barcelona.
"I do not doubt the honesty of referees but there are some things that are obvious and that people who are not hypocrites have no problem in admitting," Mourinho said.
"There were decisive penalties in the match that weren't given and this is not a criticism but something obvious."Reuse content