During a press conference, it was announced by Spain President Luis Rubiales that Lopetegui would not be taking charge of the side in Russian Federation.
Former Real Madrid star Hierro has been working in the Spanish national team set-up since his appointment as sporting director last November, with the move to appoint him as Lopetegui's replacement created to dilute the confusion around the squad.
"The federation can not be left out of a negotiation by one of its workers and be informed five minutes before the press release", Rubiales said.
"We have been compelled to act".
"The federation has its values and it has to maintain them", Rubiales said.
For the first time since 2006, there are more players from Madrid in a Spanish squad for a major tournament, with a six-strong Real contingent and just Gerard Pique, Jordi Alba and Sergio Busquets from Barca.
The club released a statement this afternoon to that effect which said: "Julen Lopetegui will be the coach of Real Madrid after the 2018 World Cup in Russian Federation".
De Gea was part of the United side that last won the Premier League title in 2012/13
Lopetegui was sensationally axed on Wednesday just 24 hours after it was announced he would take over at the Bernabeu following the World Cup.
"There's a lot to do".
Spain begin their campaign with a clash against Portugal in Sochi on Friday.
Although Lopetegui has done well with the Spanish national team, amassing their second-longest unbeaten streak of 20 games, he has limited experience at club level.
He took charge of Spain in July 2016, leading the 2010 World Cup winners to nine wins and one draw in a qualifying group that included four-time winners Italy. We are working on it. "When we know we will tell you". Numerous staff are still with us and we've watched videos about the upcoming match, so we have to be intelligent and coherent.
"I don't want to get into how Real Madrid should go about things".
It's been a turbulent few days for Spanish coach Julen Lopetegui.
"We have to stop thinking about the past and focus on our match against Portugal", Hierro said on Wednesday.More news: Amazon expands Whole Foods Market discounts for Prime members