Problem with the midfield is that we have the quantity.
Vidal, Vecino, Gagliardini, Sensi... on top we have the starters Barella, Brozovic, Hakan. That's 7 players already for 3 spots.
Vidal and Vecino are expiring, we're trying to send Sensi away, we're renewing Brozovic soon.
The money saved by Vecino is going to Brozovic, the money saved from Vidal cannot really be used now apart from someone on a loan, but that means someone has to take Vidal now. Sensi doesn't earn that much and cannot command a fee to use.
Hands are tied for a new central midfielder. On the other hand, Kolarov retiring and Dimarco moving as Bastoni's backup means we need a WBL. Perisic leaving means this new player gets to be the new starter from 2022-23. It all boils down to that. Correa being injured also adds a necessity to chase a backup striker.