for me the only likely definates are
Baines
Keane
Jagielka
Williams
Holgate
Martina
Walcott
Tosun
Stekelenburg
Pickford
Gueye
Sigurdsson
Niasse
Coleman
Richarlison
Davies
Besic
Lookman
maybe Calvert-Lewin
the rest are surplus to requirements
if Digne and Mina join then that makes 21 players and its likely that Klassen, Bolasie, Sandro and Mirallas will be given a second chance
the problem is that we are overloaded with wingers and strikers that I can't really see any of the youth midfielders / strikers getting much game time