So Atletico game you decided to put on Miki.
Barella is not as much physical as Miki. They run the same amount. Miki is hugely important on the left side of midfield. anyways., lets' not play Miki for a while and you will see the result. It's clear that Zielinski is not ready yet. Yesteday's game has shown that. Good luck with Frattesi.
Physicality is not limited to running distance or purely stamina, and even if we are talking stamina only, besides running distance the tussling part and how you run (sprint, jog, walk) also demand lung capacity and muscle endurance differently, and Barella is way ahead.
There is a reason why Mkhitaryan struggled so much against Atlético de Madrid along with Darmian, like a world class player doesn't have be world class in physicality, but you cannot be inferior to a point it can hinder your game. Also I am not faulting him for the game, but that game shows you why he is not WC anymore, if he ever was one.
Don't get me wrong, I still think Mkhitaryan has a huge role to play in this team, and I appreciate his football intelligence, skills and consistency, which he will be looking very good for most the games, but not when we are playing some very strong opponents in CL. He is basically how Dzeko was good for us. I never deny how important Mkhitaryan is for us, and yes, Zielinski still needs time, I have been watching pre-season too, and I agree.
To me Barella is our only WC midfielder, Hakan is only borderline; however, we still do have one of the top midfields in Europe, cause football is never evaluated based on pure individuals, like Riquelme might be better than Xavi or Iniesta individually for game impact alone, but I cannot see how you pair Riquelme with anyone and can make them better than Xavi + Iniesta.