The interview has just finished and Louis van Gaal gets up to leave. “Interesting, eh? Interesting,” the Manchester United manager says, almost inviting approval. “You’re all coaches now.”

There was a smile and a glint in the eye as Van Gaal delivered his parting refrain, but the underlying message was clear: “Listen to me, I know what I’m talking about.”

Over the previous 22 minutes in a ballroom at the Mandarin Oriental hotel, where United are staying in Washington DC on the third leg of their pre-season tour of the United States, Van Gaal had offered a tantalising glimpse of what it must be like to work under such an exacting individual. There were flashes of his dry wit and undoubted charm but also the