It is a risk not to sign a fourth centre-back.
It would also be a risk to sign one as doing so would curtail the space within which to develop Hoever, van den Berg and Koumetio.
Milot Rashica is available for around £15m if Werder Bremen are relegated; they are currently second from bottom, two points off the relegation playoff place.
El Desmarque reporting that Diego Carlos is set to join in the summer from Sevilla; £64 m buy-out clause activated ahead of Real Madrid. He's a 26 yo Brazilian CB.
Reports that Liverpool are to sign Sam McCallum; a 19 year old English left back from Coventry City in January and then loan him back for the remainder of the season.
The difficulty for Palace with regard to Zaha is that the player wants to sign for a club in European competition and not have to move away from London; it's problematic to create an auction involving one club with no money (Arsenal) and one who won't spend any money (Spurs).
Linked with signing Diego Llorente for £22m from Real Sociedad. https://www.caughtoffside.com/2019/05/24/liverpool-closing-in-on-transfer-of-la-liga-defender-for-e25m/
Liverpool received around £70m from UEFA last season in prize money alone; add in gate receipts from UCL games at Anfield and sponsorship bonuses and we are looking at around £100m in additional revenue last season with a similar amount to follow this season.
As Keita's final price was contingent upon RB Leipzig's final league position we obviously didn't sign him until 1st July 2018; ipso facto he is a signing in this window.
I don't think that Fekir will feature much for France this summer; Deschamp appears to view him only as an option off the bench rather than one of his starting forwards (Griezmann, Giroud, Mbappe or Dembele).