Proof of concept. It is Thomas Tuchel’s latest buzz phrase. The England manager has dropped it into the conversation pretty regularly since the Friday of last week when he named his squad for this international window, the one that was always going to decide whether his team finished first or second in their Nations League group.
By it, Tuchel means a test of his methods, what he is trying to build – or, more accurately, fine-tune – as he turns his gaze towards Euro 2028 and tries to move on from the devastation of the World Cup semi-final exit against Argentina. The test does not come any bigger than the one which faces him and his players in Madrid on Sunday night.
