Lopetegui has endured a mixed managerial career thus far, but has history with Los Blancos, having managed the club's B team between 2008 and 2009. Lopetegui favors his adversary, though.
The Slovenia international is currently being watched by Liverpool, with Jurgen Klopp keen on signing a new No 1 this summer, however Real are favourites to complete the deal. United have grown dependent on him.
"The most important thing is to support the team of France", he told TF1.
His name had been briefly mentioned among many others as a possible successor to Zidane, who stepped down on May 31 after leading the club to a third straight Champions League crown, although a move seemed highly unlikely. For example, leaving out Chelsea's Alvaro Morata from the Spain squad in favour of Valencia's Rodrigo.
Lopetegui was part of the starting eleven along with Julio Llorente, Chendo, Fernando Hierro, Jesus Solana, Esteban Granero, Michel, Adolfo Aldana, Rafael Gordillo, Sebastian Losada and Paco Llorente.
Here, The Boot Room highlight six star players that will not be at the World Cup. To play for a manager he knows well, who he has experienced success with, has to be appealing.
After the tournament, Spain will have to find a new boss ahead of the new UEFA Nations League, in which they will open against England and Croatia in September.
Bale has endured two years of injury set-backs and is in fact a target of United.
It seemed nobody wanted the job but Lopetegui has leapt in to take the reins from next season onwards.
"One more year!" they chanted on repeat at Edwin Van der Sar in his final game at Old Trafford at the end of the 2010-11 season.
Get the latest World Cup news updates. He replaces Zinedine Zidane, who shockingly and abruptly left the club on the final day of last month. "These are personal decisions that I cannot judge".