The black panther!
Simply the best CB in the world
I said this ~ one year ago because he had a really good start to the season and went on to be one of the best players of the season for us. The start of this season haven't looked as good all the time but that doesn't necessarily need to mean he's regressed or become more mistake prone.
His role has become more advanced as Pioli has made our defense more aggressive. It could be because of the CB's at his disposal can handle that type of defending or because we don't have Kessie in midfield anymore or a combination of the two. But what is clear to me is that our defensive shape and approach has changed from last season when we where stacking clean sheets.
Our CB's are really really aggressive and will hunt the striker (or attacking mid) all over the pitch. That's a clear instruction from the coach - they did it already last season but even more this season. I haven't seen that from other teams, could anyone give examples of other teams that play like this?
A CB that was expert at this type of defending was Nesta. Very aggressive, stepped out of the CB comfort zone all the time and rarely made any mistakes. It's up to Tomori and Kalulu to adapt to this now and make it an art just like Nesta did. Until then, we will probably see them in situations where it looks like they've made a mistake, when in reality it's because they are asked a tough task not many CB's can handle and will be "victims" of the team approach. If they do manage to come close to Nesta in this type of defending, we are golden, and if not the coach will probably change approach and play his CB's more like last season.