If we are aiming for say sneaking a Europa League spot next season as a goal then this is how I'd view our current squad, providing they're all fit.
Nowhere near the level needed-
Alioski
Roberts
Casilla
Forshaw (mostly because of injury)
Costa (Tough one as he has it in him somewhere but isn't consistent with it)
Good enough as back up but not first team-
Ayling (though still first choice next season)
Dallas (may seem harsh but he to me is someone we could never let leave, he will still play most games but not as first choice in a particular position but as a back up in almost every position)
Cooper
Klich (has really found his level)
Shackleton (I still think he needs a full season on loan somewhere to really develop, this in/out nonsense never knowing where he is best isn't helping him at his age)
Poveda
Need time to develop and we will see-
Struijk
Meslier
Actually good enough to take us to the next level-
Raphinha
Phillips
Koch
Llorente (We haven't seen it but he in what little I saw for us and Spain looks a good player to me)
Rodrigo
Harrison (Unsure, was tempted to pile with the back up options but I think he will grow the more he plays against top quality opposition)
Bamford (Whilst I'm saying he is good enough we need a proper back up striker for when is isn't on it)
We aren't going to overhaul a squad and I wouldn't want us to, but if the top 4 can he shipped out of the club then add 2 new central midfielders, a proper left back and another striker I think we set ourselves up much better for the coming season particularly if we can avoid the rotten luck with centre backs we've had this year. Add to that hopefully likes of Huggins, Drameh, Gelhardt, Cresswll, Kenneh, Greenwood, Summerville, Jenkins, Mckinstry, Davis, etc etc all potentially able to develop and step up we should be fine to challenge for a spot between 10th to 7th next year.