“I look behind me and I see Mikel Merino and I think: ‘I’m calm as can be,’” Luis de la Fuente said when at last the heart rates had returned to normal. Everyone else’s heart rates, anyway. In those moments when time is running out and the tension is running high, there’s something about Spain’s coach. And there’s certainly something about the midfielder.

On the afternoon before Spain faced Belgium in their quarter-final, De la Fuente had an attack of the giggles as he recalled how when he was a kid only three television events gathered his family around the screen: the national team, Eurovision and the gloriously silly, inexplicably bizarre gameshow Un, dos, tres (whose UK version was 3-2-1).

He had watched Spain fall at this stage repeatedly, the quarter-finals a barrier they could not overcome, knocked out in 1986, 1994 and 2002, but now it was his turn to face it instead of stress here he was falling about, crying with laughter.

De la Fuente could not control himself then; the next day, as Spain faced that barrier again, on edge once more, he could and so could his players. They had 68% of the possession, three times as many shots, but as time slipped away against Belgium it was still only 1-1 and there had been a couple of scares, the kind of moments that once would have had the fatalism flooding back, players convinced they were about to get caught.

Spain, though, sought the winner relentlessly, but not desperately: this was not just balls into the area, an endless catalogue of crosses. Instead, there was a clarity, a calm that came from the touchline too.

And from behind it. It helps to see Merino there, that’s for sure. Merino has scored three goals for Spain at major tournaments, one at Euro 2024 and two at this World Cup: all of them as a sub, all of them winners that sent Spain through, they have come in the 119th, 90+1 and 88th minutes. If you are going to do it, do it dramatically. Now that’s what you call clutch.

All of them were celebrated the same way, Merino circling the corner flag in honour of his father, who did the same after getting the winner for Osasuna at Stuttgart 35 years ago. At Euro 2024, Merino headed the winner against Germany in the same stadium where his father had scored, taking Spain into the semi-finals. Now, in Dallas and Los Angeles he did it again. Twice in four days. His dad, Ángel, was in Dallas to see it, wearing lucky, novelty socks with an image of his son’s header in Stuttgart on them. Merino’s two-month-old son, Marco, whom he has barely seen, was not, so he did it again.

Merino had been on the pitch one minute and 56 seconds. In total, he played five minutes plus stoppage time against Portugal and four minutes against Belgium, but it was enough to take Spain into the quarter-final first and then into the semi. That barrier had been broken for only the second time. Spain have reached one semi-final before, when they were champions in 2010. Since then, they had not won a knockout game at a World Cup. This may feel normal, but it is a big step.

“I don’t know how I’ll explain it to [my son]: luckily there’s YouTube and internet and I’ll be able to show it to him because it will be hard to do with words,” Merino said. “Since they weren’t there in the round of 16 I had to repeat it so they could live it in person. I’m very happy they are here because they are my strength and I am sure that part of the luck I have had in the ball falling to me is because of the good energy they have given me.”

But it is not just luck. There was a reason De la Fuente was so determined to wait for Merino through an injury that meant he played less than half an hour since February. A reason, or many reasons. “Mikel is super complete, very versatile. He’s played as a 6, an 8, a 10 and a 9, and he does all of those things so well,” De la Fuente said. “He can be the best striker, the best second striker, the best midfielder. Why? Because he has exceptional understanding, a feeling for what the team needs and a calmness. He has commitment, solidarity.

“The story won’t always end this way. But you do know you’re closer to it because the players know what they have to do, and they’re very good.”

It won’t always end this way, no, but the coach got it right again. When it comes to the big decisions, he tends to. Replacing Pedro with Fabián Ruiz was a big call. Half an hour in, the PSG midfielder had scored the opening goal. When De la Fuente had removed Dani Olmo, arguably Spain’s best player against Portugal in Dallas, most wondered what on earth he was thinking … until Merino scored the winner. In Los Angeles, he did it again and it happened again.

It is easy a posteriori, the coach reminded everyone after the quarter-final, but his decisions are taken a priori. They are also taken carefully, he said, with analysis, thought and, above all, a knowledge of his players. Taken with tranquillity, too, and executed that way.

De la Fuente drew on a line from Marcus Aurelius’s Meditations, which he is reading and which was quite the contrast to Un, Dos, Tres. He has talked of his faith and there has been an ease about him, as if he just knows, as if it is written.

Almost the only thing that has annoyed him is that others did not have the faith he and his players have; where, he wondered in that first fortnight when his confidence was not always shared outside the camp, is the negativity coming from? Where most managers run a mile when people talk about favourites, he and his players have embraced it from the start. Why not?

“We’re not afraid of France,” Lamine Yamal said. De la Fuente said: “It’s legitimate to think we can beat France; they’ll be as worried as we are.” Which, on the evidence at this World Cup so far, is not worried at all.

“I look at our players and feel calm,” De la Fuente said. “They appreciate that calm, too. If they saw me out of it, beside myself, histrionic, saying wild things, this team wouldn’t respond well to that. This is a team that has heart, the stimuli it responds to are understanding, affection and commitment. That’s what moves us.”

If not, there’s Mikel Merino. What could possibly go wrong?