David de Gea is almost certain to stay at Manchester United after Jose Mourinho moved to appoint one of the Spaniard's most trusted confidants as the club's new goalkeeping coach.

Emilio Alvarez Blanco, 44, was the coach who oversaw De Gea's breakthrough at Atletico Madrid.

When Quique Sanchez Flores, Atletico Madrid coach at the time, and his keeping coach Alvarez took over, De Gea, then 18, was in line to be sent out on loan.

David de Gea's mentor at Atletico Madrid has been appointed Manchester United goalkeeping coach

Emilio Alvarez Blanco, left, played a major role in De Gea's early development at the Spanish club

Alvarez picked out De Gea to be Atletico's best goalkeeping option when others did not believe in him

But Flores asked Alvarez's opinion on the club's three goalkeepers — Sergio Asenjo, Roberto and rookie De Gea.

Alvarez said: 'El Nino (the boy) is the best one.' Flores replied: 'Are you serious? He is weak physically, he looks like a little boy.'

They developed a training regime and by the end of the season, De Gea was the first-choice goalkeeper of a Europa League winning side.

Alvarez is a close friend of Jorge Mendes, Jose Mourinho's agent. It is likely that Mendes and De Gea recommended the coach. The recruitment of Alvarez is the clearest sign yet that De Gea now sees his long-term future to be at United and holds aspirations to be the club captain.

At Atletico, Alvarez allowed De Gea's father, Jose, a former goalkeeper himself, to observe training.

In an interview with Sportsmail in 2014, Alvarez said: 'David's dad, Jose, is his best coach. Let's go into a dream-world for a second, where I am the coach at United. My first decision? Let De Gea's father into the training. Why not?'

Alvarez was confirmed as a member of Mourinho's coaching staff on Thursday