It has long been said that you cannot replicate the atmosphere of a matchday during training drills, an oft-heard excuse in the wake of a penalty-shootout defeat, for example.
Not now. As West Ham proved over the weekend, if you want to recreate that unique game-day experience, simply pop your kit on and play a practice match inside your empty stadium.
This is the world in which the Premier League will exist during the coming months, where what would ordinarily feel like an inter-squad kickabout is actually not too far removed from the real competitive action.