England played their part in a thrilling encounter at Wembley, showing plenty of attacking quality while also displaying some worrying moments of uncertainty when attempting to build from deep.
The result could have been very different had Harry Kane converted his 53rd-minute penalty. Instead, the European and world champions held on to claim a 3-2 victory, leaving England to begin their Nations League campaign with defeat.
“I think we did everything today to beat Spain,” said Tuchel, who has been under pressure since England's World Cup semi-final defeat to Argentina in July. “Details matter on this kind of level.
“The amount of mistakes, clear-cut mistakes, was too high on our side today unfortunately and in the last 20 metres they were more composed and more clinical.
“Still, we had them and we had the chance to beat them.
“We will keep on pushing this team. We proved at the World Cup that we are capable of doing it in tournaments.
“Today we cannot prove it with the result but I think the way we played was enough to beat them, but it’s not proven in the result.”
Spain benefited from England's mistakes for both of their first two goals. Marc Guehi was dispossessed by Lamine Yamal inside the opening two minutes, while Nico O'Reilly later surrendered possession and allowed Alex Baena to score.
Those errors came either side of England's response, with Anthony Gordon and Harry Kane both finding the net as the hosts briefly turned the game in their favour.
There were further moments when England's vulnerability at the back could have proved costly, but they survived those occasions and remained firmly in the contest.
With England trailing 2-1, referee Davide Massa initially waved away a challenge by Rodri on Jude Bellingham. After being sent to the pitchside monitor, however, he reversed his decision and awarded England a penalty.
It was a huge opportunity to level the match, but Kane's effort crashed against the crossbar, leaving Spain with the advantage.
For Tuchel, the performance nevertheless offered evidence that England can compete with the strongest teams, despite their recent record against sides ranked inside the world's top ten.
England had won only one of their previous 15 matches against such opposition, a statistic that prompted an irritated response from the German when he was asked about it.
“That’s why I was surprised about the World Cup because I think, at the World Cup, we beat three top-ten teams,” he said.
“Interesting that in the moment where we win, nobody brings it up, but when we lose one we come up with statistics.”