So this is my take on the squad come the end of the window, (X) = cover:
GK: Kinsky, Dubravka, Austin
RB: Porro, Gray (will be primarily used in CM, but he is the cover here)
CB: Senesi, Danso, Van Hecke, VdV, Davies
LB: Udogie, Robertson (Davies)
6: Fernandes (Gray, Bentancur, Bergvall)
8: Tonali, Bergvall, Bentancur (Gallagher, Gray)
10: Gallagher, Maddison (Deki)
RW: Savinho, Kudus, Deki
CF: Marmoush, Solanke (Gakpo)
LW: Gakpo, Tel (Savinho)
To return: Odobert, Simons
Which means Richy will go when Marmoush is signed - we're stuck with Solanke for this year, given his injuries, maybe Kroupi could be the upgrade on him at the end of the season?
For me, then, it's a shoot out between Tel and Odobert for reserve/rotation option at LW if Gakpo signs and then Simons, if he can regain his form post ACL, replaces Maddison in the squad longer term (27/28). Depending on their recovery, I could also see one of Deki or Kudus going next summer.
All of which is 25 places, doesn't account for players like LWB, and pays no regard for the HG rules, which are less of an issue this season because of the lack of Europe. I hope far cleverer people than may are paying attention to that in terms of our squad building!