I don't get the obsession of keeping Pjanic. Yes, he is our best midfielder right now, but turning down 80M (especially 100M) is a no brainer.
He's too metal fragile and disappears in the big games if he makes a couple of mistakes. In all the CL games we have struggled, he has has been one of the lowest performers. Even Allegri has some time ago commented that he needs to improve on keeping cool and stay focused if he makes some mistakes during a game.
Also, he lacks defensive and physical attributes meaning we have to play 3-man midfield which limits only 3 spaces available for Ronaldo, Manbro, Dybi, Berna, DC, Cuads and potentially Pjaca.
However, replacing his creativity in midfield will be difficult, especially as I only see SMS, Pogba and Kovasic (of those rumored to us) on similar level. However, they do also have that physical and defensive ability to allow us to play 4-2-3-1.
In other words, if we could sign one of those by selling Pjanic, it will be 10/10 mercado for me.
If not (Man U not letting Pogba go, SMS still too expensive and Kovasic staying at RM), I would still prefer selling Pjanic, buying a less expensive replacement who is less creative but more physical and defensive present (even Golovin would do, even if he doesn't quite fit that description) while also giving Bentacur more playing time to develop him.