If you want a measure of how private a place the dressing room was when I was growing up at Manchester United, consider this: even Sir Alex Ferguson would knock before coming into the dressing room at the Cliff, the old training ground. The dressing room is for the players - and the players only.

From United's point of view, it is always difficult to tell just when a young footballer is going to mature into a first-class professional ready to play at the highest level, but the story of how Pogba slipped away from United has more than one strand to it.

I first remember Wayne Rooney from a game at Old Trafford in 2002 when he came on as a late substitute for Everton and, in a brilliant 15-minute performance, skipped past me on a couple of occasions.

My view is that you show Messi one side or the other, and if he goes past you, he goes past you. But if he slips it through your legs, then you have to obstruct him and take the foul. Just don't ever let yourself be nutmegged.