Spain sacked head coach Julen Lopetegui after he was named the new Real Madrid boss – two days before their opening World Cup match against Portugal.
Real Madrid announced on Tuesday that Lopetegui would succeed Zinedine Zidane at the Bernabeu on a three-year-deal.
The Spanish football federation (RFEF) said it had dismissed the 51-year-old because the negotiation occurred “without any information to the RFEF”.
The World Cup in Russia starts on Thursday.
“I know it’s a very difficult situation. I know there’s going to be criticism whatever I do,” RFEF president Luis Rubiales said.
“I’m sure this will, in time, make us stronger. I admire Julen very much, I respect him very much. He seems a top trainer and that makes it harder to make the decision.
“You can’t do things this way, two or three days before the World Cup. We have been compelled to make this decision.”