I believe the main problem is not that Sarri didn't have the players for his system, but the very fact that he's got a system rigidly requiring very specific types of players (or even more, not the types of players, but specific players, like Jorgihno). And the worst part is that this system has not even proved to be effective in the long run, quite the opposite, actually. That's why no one should blame the management for not completely rebuilding the squad for Sarri's system - why would they do that? They just shouldn't have signed this manager in the first place.
I'm writing all of this without any sarcasm or irony. The approach Sarri's relatively good at is suitable only for a small club that: a) have nothing to lose; b) can sign a lot of cheap unknown players fitting required profiles; c) can give him several years to make things work and to grow that bunch of nameless players to a state when they are a group of solid hardworking workhorses, grateful for their progress and quite successful careers. That's something he can get at any team below the 6th place, and he will be great at such a job. At the same time, he will never have anything like this at Juventus. So, it doesn't really make sense to continue this story after the CL is over.
I'm writing all of this without any sarcasm or irony. The approach Sarri's relatively good at is suitable only for a small club that: a) have nothing to lose; b) can sign a lot of cheap unknown players fitting required profiles; c) can give him several years to make things work and to grow that bunch of nameless players to a state when they are a group of solid hardworking workhorses, grateful for their progress and quite successful careers. That's something he can get at any team below the 6th place, and he will be great at such a job. At the same time, he will never have anything like this at Juventus. So, it doesn't really make sense to continue this story after the CL is over.
