So, going into next season, I'd guess we look like this:
---------------------------------#9(Martial)----------------------------------------------------
Sancho(Rashford)---Bruno(VDB)-----------Antony(Garnacho) but Sancho is the actual RW backup
--------------------#8(Eriksen)-Casemiro(McTominay)----------------
Malacia(Shaw)-Lisandro(Lindelof)-Varane(RCB)--------RB(Dalot)
--------------------------------GK(Dubravka)--------------------------------------------
and Cristiano, Fred, Maguire and anyone else not mentioned over the age of 22 all leave. Elanga, Zidane Iqbal or Hannibal, one of the fullbacks (Williams, Laird or Alvaro) and maybe a CB gets promoted along with a 3rd keeper. That's a squad of 26 plus another young player or two who makes it.
So, that's a 9 and #8, a starting RB or at least real competition for Dalot, a young RCB with potential to backup and in time hopefully replace Varane and a starting GK.
Seems doable. Wouldn't be shocked if the RB is signed in January with Wan-Bissaka going out.
At the minute, I'd guess this based on rumours and educated guesses, though it will be wrong:
#9 - Osihmen
#8 - Koopmeiners, Dutch and is left-footed which might help with balance, he's doing well at Atalanta and they'll sell
RCB - No idea, though the Bundesliga seems to have a lot of these guys coming up after starting in Ligue 1
RB- Timber (would be a 3rd very expensive signing but that seems plausible)
GK - Robert Sanchez from Brighton, who will want to play for a bigger team to get a real shot at starting for Spain and Brighton will probably lose him and another key player like Mac Allister, Caicedo or Trossard for big fees