England head coach Thomas Tuchel during the World Cup semi-final loss to Argentina in Atlanta
England's proof of progress and the lessons learned by head coach Thomas Tuchel since the disappointment of World Cup semi-final defeat by Argentina will be put to the sternest test when they face holders Spain in Madrid.
Spain present the toughest assignment England could face, with the world champions' unbeaten run – in which they claimed the sport's biggest prize by beating Argentina in New Jersey in the summer – now stretching to 43 games.
Luis de la Fuente's side last lost - to Colombia - in March 2024, winning 34 games and drawing nine in the intervening period, during which they also became European champions, beating England in the Euro 2024 final in Berlin.
Little wonder, then, that England captain and Ballon d'Or winner Harry Kane describes Sunday night's visit to the Metropolitano Stadium as: "The perfect opportunity to try and prove ourselves."
Tuchel, who revealed Leeds United's James Trafford will get another opportunity in goal as he continues to alternate with Jordan Pickford, clearly feels the same as he added: "This will be proof of concept on the highest level. It's the biggest test in world football. Spain are unbelievable on an incredible run.
"Spain won the last big titles. We are trying to take it away from them. We are up for it. We are in a good moment to push our limits. We are up for something spectacular."
It was a message echoed here in Madrid by England midfielder Declan Rice, who said: "It's a massive game.
"I don't think you can get much bigger than a Champions League final with Arsenal or a World Cup semi-final against Argentina, which I've played in, but when you are playing against the world champions in Spain there is no greater incentive.
"It's the sort of game that brings out the best in us. We want to play against the best teams and the best players. It will show where we are as a group. We're going to see where England are at."
Spain are particularly formidable on home soil, unbeaten in 20 games - winning 15 and drawing five - since a 2-1 defeat by Switzerland in September 2022.
England's most recent win in Spain was a 3-2 triumph in a Nations League encounter in Sevilla in October 2018, their first away victory against them for 31 years.
Yet England came closer than most to piercing Spain's air of invincibility, even though they lost 3-2 at Wembley in September, when a rare Kane blemish from the penalty spot prevented them taking a potentially decisive 3-1 lead.
Spain subsequently punished England and Kane, who will be hoping for better fortunes when the countries meet again in the latest Nations League encounter.
England arrived in Madrid on Saturday evening having reeled off four successive victories since that Wembley loss, the latest of which was a 2-1 win against Croatia at Wembley on Thursday.
Spain will present an altogether different opposition, but also a barometer of whether England have moved forward since the World Cup, when Tuchel was heavily criticised for what was perceived to be a negative approach in the 2-1 loss to Argentina in Atlanta, especially after Anthony Gordon put England ahead.
'The decisions Tuchel made cost England' - analysis
Former England defender Matthew Upson, who will be in Madrid for BBC Radio 5 Live, told BBC Sport: "Harry Kane saying this is the perfect opportunity for England to prove themselves is a great way to build this challenge up.
"I wouldn't expect anything less from him considering where he is at now, where his belief level is and what he wants to achieve.
"Harry is achieving incredible personal accolades like the Ballon d'Or, but he won't rest there. He will want a team honour with England, and if you play against the best in the world there is no better barometer of where you're at as a group.
"It's going to be a very interesting test. It's fair to say we didn't see England at full flow against Croatia, so now we will see if they adjust, improve and produce something of their best, which they will have to do if you are going to get any sort of result against Spain in Spain.
"If England get a point, or even better a win, against Spain with their record, at home and away, we will come away thinking they are at a high level.
"If you get a result, you will have had to play really well because you won't do that with anything else.
"By that, I don't mean a blistering game. I just mean doing things well and showing the level you are at."
In the aftermath of that World Cup loss to Argentina, the post-tournament process embarked upon by the Football Asssociation included canvassing the opinions of the whole squad, where it emerged it took place at a "full and frank" meeting with Tuchel at the start of the September international break.
Kane and Jude Bellingham were understood to have given forthright views, where the approach in the devastating loss to Argentina was a key theme.
There is now believed to be a feeling in the squad that Tuchel has taken on the lessons of Atlanta and is focusing on a more positive approach.
Spain won Euro 2024 and this year's World Cup
Upson said: "England are still a bit of a work in progress. We have two or maybe three players who are playing some of the best football across Europe and the world at the moment. I am thinking of Kane, Bellingham and, at times, Anthony Gordon.
"The key is utilising that, then getting the rest of the team to a place where it can support that and deliver its own world-class support. This is the challenge for Thomas Tuchel."
"England are adopting a more positive approach, but look a little vulnerable defensively, which is maybe the compromise.
"Yes, England could have been 3-1 up against Spain had Harry Kane scored his penalty, but don't forget we could easily have been 3-0 down before we scored."
The intense environment of facing the World Cup holders on their own turf will also be a forensic examination of England's mental progress as well as footballing prowess.
Upson said: "The biggest thing to fix after the World Cup was player reaction and player belief when we're in certain situations, especially if we go ahead and all of a sudden the game is difficult, as it was against Argentina. What is our mindset going to be?
"Since then England have tried to play much more freely, openly and confidently. That's how I see it. That's how we played when we won 7-0 in Croatia. We were free, open, positive. Belief was through the roof.
"This is why this test against Spain is great because you will get tested to the maximum there. If England go ahead, let's see how they do and what they do. If they go behind, let's see what we do.
"Against Spain at Wembley, I saw a reaction at half-time from England, which was fantastic. We should have gone 3-1 up with Harry's penalty, and in that 15 minutes after half-time we were super positive, aggressive in our decision-making.
"This was another ideal situation to test that. They came through that really positively. It would be great if we get another test like that on Sunday.
"It it all plays into what Harry Kane said. This is something which will test people. It's a really significant game for England on a lot of levels."
Who would make your England-Spain combined XI?
'No racism in Spain' – De la Fuente message for Tuchel
White has 'exciting future' despite boos - Rice
