The world of football was stunned on Wednesday when Spain took the decision to sack Julen Lopetegui just one day before the start of this summer's competition.
The RFEF was unable to accept Lopetegui's handling of the situation, and relieved him of his duties, with former Real Madrid and Spain centre-back Hierro stepping forward to lead the country at the World Cup.
"We needed to move forward as quickly as possible. These were not pleasant times. Julen Lopetegui helped us qualify. He played a major part for us," Ramos told reporters at a press conference.
"But the sooner we focus on the World Cup, the better for all of us. There are few people more qualified than Fernando to cover after Lopetegui's departure. We've all admired him as a player for a long time. So he's the perfect candidate to cover this post."
Spain will open their 2018 World Cup with a clash against Iberian rivals Portugal on Friday night.