Alderweireld and Meunier would improve our defense, and they won't cost too much.
It seems that Pogba is on his way out so Fernandes would be a decent replacement, plus we would have the money to spend in a couple of midfielders like Van de Beek, Tielemans, Neves, Barella, Ndombele, Rice, Ndidi, Doucoure, etc. We should get at least 2 of them considering Herrera will leave and Matic should not start.
For the right wing, Sancho is the dream but I would be okay with Pepe and another attacker like Felix/Dybala (as replacement of Sanchez). Finally, Icardi in a swap deal with Lukaku if he doesn't want to continue.
If we need to build a new midfield of 3, who would you buy?