In all seriousness about yesterday's match, I liked him at LCB. His physique makes him really versatile as a defensive player, could probably play him at DM and he wouldn't look too out of place if you don't ask too much of him.
I think he may be designed as LCB for 3-man defense. He's a weapon with the ball at his feet when he can quickly get into space and doesn't need to play meaningless one twos to play out of tight areas. He's strong enough to beat people 1 on 1 and get to the box whichever way he wants, but he'll near always be stopped when there's sufficient cover for his marker.
I hope we see him at LCB this month in 3-5-2/3-4-3 again due to injuries or otherwise. He brings a lot of good and actually makes the Marcelo positional horror seem bearable particularly when has Casemiro to help too. We all know Zidane loves 4-3-3 and will not have it long term, which is a fucking shame, but he may be convinced to play it more often when he sees how much better our stability is when we don't need to worry as much about CKM midfield being caught out and 3 CBs are capable as a unit at snuffing out danger.
Would love to see the following at some point again
------Eder/Nacho----Rafa----Mendy-------
Carva--------------------------------Marcelo
------Modrić/Fede--------Kroos/Case-------
------------------Marco/Eden---------------
-----Marco/KB/Mariano-----KB/Eden/Vini---