It was in an airless room, in the bowels of the Bernabéu, that we learned a little more about the young guy with the sloping shoulders and Tintin haircut who had picked his moment well to turn down the volume on his critics.

"In Spanish we call it cresta cabeza," Eric Steele, the goalkeeping coach who has taken almost paternal care of David de Gea at Manchester United, explained. It means, literally, quiff-head. "Any criticism goes off that quiff. That is the great thing about him. He's able to say: 'Right, fine.' He might have dark moments but he keeps them away from the training ground. If he is ever hurt, he doesn't show it."

Steele can pass off a little Spanish because he has been learning the language to help the lines of communication. De Gea's English is evidently improving, too, on the back of his twice-weekly lessons. On Tuesday, sitting beside Sir Alex Ferguson in a news conference in Madrid, he had wanted to show it off. "He was disappointed he got only two questions," Steele disclosed. "He was ready to answer some in English."

It is a brave man who is willing to try a new language in front of the world's media but, if there is one thing we are coming to learn about De Gea, it is that the 22-year-old is not short of courage.

There have been lapses, as might be expected of a goalkeeper his age, and it is a brutally two-faced media when the people stampeding to bury him a few weeks ago are now trampling each other out of the way to lavish him with praise.

Steele has said himself that De Gea was "slightly disappointed" with his first season in Manchester but perhaps now it is clearer why Ferguson, a manager who has described a goalkeeper's best attributes as maturity and experience, was prepared to replace Edwin van der Sar with someone half the Dutchman's age.

It was, Steele admitted, a calculated gamble. Van der Sar was 34 when he made his United debut and nearly 40 when he left. Peter Schmeichel was 27 when he signed. Fabien Barthez was 29 and Tim Howard 24. De Gea was 20 when he arrived in Manchester from Atlético Madrid for a fee of £18.9m. "The manager missed out on Petr Cech when he was younger and he didn't want to do that again. Joe Hart was the other one. The manager just said if this guy is as good as we think and we have scouted him strongly, then we don't want to miss out on him like we did with Petr Cech."

It has been a difficult journey at times. "You bring a boy into the Premier League at 20," Steele said. "It's not easy. He's learning in the toughest environment in the world. But the one thing he has is fantastic inner strength. We teach him that the calmest man on the field has to be the goalkeeper. And one of his great strengths is his calmness.

"There have been dark moments but he has his family close to him. He doesn't read the press. All the other mediums are there, which he knows about. But everything that has been going on around him for the last four or five months … trust me, he's very mature for his age. He's had to be because you're not just replacing a goalkeeper in Edwin, you're replacing a legend.

"It's not just about the shot-stopping. There's more to it. Put it this way, if you think about what David has been through, he has to have inner strength. He has dealt with it. And he's such a likable lad. He hasn't come in swearing and squeaking. He's just got on with his job."

What a job he did, too, against José Mourinho's team. As Steele put it: "He was born in Madrid, played for the enemy. There were all these different pressures on him – but you wouldn't have known."

De Gea had left the Bernabéu saying merely that he was "very happy" with his performance. Ferguson had described him as "superb", making "three or four top saves" and sparing United a potential ordeal with that slight yet decisive touch, at full-length, to turn Fábio Coentrão's shot against a post early on.

Steele blew out his cheeks in admiration. "That was the one. If we go one-nil down to Real Madrid after five minutes at the Bernabéu, that makes things a lot harder. He saw it late – one of their boys might have been offside in front of him – but he got a finger to it. Some [goalkeepers] may have had the anticipation. David also had the speed of the first-step movement and that great long reach to get enough on it. That's the fine line for a goalkeeper. That's why a goalkeeper can be a hero one moment and zero the next."

The key, of course, is consistency. De Gea will almost certainly slip back again at some point and the scrutiny will not let up, as it never does at a club of United's size.

"It's the variation of the Premier League," Steele continued. "We knew he had to go to places like Stoke, Birmingham, Wolves. That's what he's having to learn: each week is a different challenge. He's still growing physically. He's working hard on that. He'll get stronger physically and that will help."

It helps, too, that De Gea is in a working environment where they shelter their players. Ferguson and his staff have retained their trust in the Spaniard, accepting there will be mistakes, just as there were when Schmeichel, the greatest of them all, first arrived in England.

"We have a staff that closes ranks, stays together," Steele said. "We know what we have. We bring in a lot of young players here. The manager has always done that and, if you're bringing in young players, you have to have confidence in them and let them build and thrive. We just put the shield up. You're there to be shot at but that's fine, you deal with it. And David will be fine. He has always been a goalkeeper. He believes he was born to be a goalkeeper."