Can't say what I think the club will actually do, but I think we should aim for a 21/22 players roster at max. No need to keep 28 players on the payroll when some of them barely see the pitch throughout the entire season.
Players that should leave: Honda, Ocampos, Mati, Gomez, Poli, Montolivo, Locatelli, Vangioni, Pasalic, Bacca (and MDS who seems to be a goner).
Players that we should buy: De Vrij, Rodriguez, Kessie, Fabregas, Keita, Aubameyang (or any top striker for that matter).
How we should be playing: 4-3-3
Donna
Abate - De Vrij - Romagnoli - Rodriguez
Fabregas - Kessie - Bonaventura
Suso - Aubameyang - Deulofeu
Bench:
GK (preferably someone with experience but not Storari)
Zapata
Paletta
Calabria
Antonelli
Sosa
Kucka
Bertolacci
Keita
Lapadula