I love this guy so much. Arteta looks like a conservative little shit of a manager, constantly worrying about whether his belt will be enough to keep his pants up or if he should have put on his suspenders as well. But then he pulls stuff like this out of his hat and you can't help but like him a little bit.
It's like he just woke up one day and told Calafiori: "You're Messi now, but more mobile. Now go out there and play." And Calafiori on his part just shrugged and went along with it.