Lopetegui was replaced by Spain's sporting director Hierro after agreeing to take charge of manegerless Real Madrid after the World Cup without notifying the Royal Spanish Football Federation that he was in talks with the club.

"The resignation of Julen [Lopetegui] is a difficult moment, but Fernando is the best option in this situation. We admired him during his football career... A very important match with the European champions is awaiting us," Ramos told journalists.

Spain, who won their only World Cup in South Africa in 2010, will face reigning European champions Portugal in Sochi on Friday, before also playing Iran and Morocco in their other two Group B matches.