Barcelona don't have the luxury of buying as many players as they want. Unlike Real Madrid, who can buy any player they want, Barca's financial problems mean they have a spending limit. Therefore, Barca need to build a very balanced squad. Therefore, for Hansi Flick to be successful, he will need to keep players like Vitor Roque, Eric Garcia and he will need to know how to get the most out of every player at the club. For now, Hansi Flick's job is not easy and Xavi said before leaving Barca that Flick must be ready to suffer.
It's difficult to select who stays and who leaves right now for Barcelona. If you ask me, I'll say Raphina, Araujo, Frankie De Jong and Ferran Torres should all be sold likewise that Vitor Roque guy. Frankie De Jong is solid as fvck but believe me when I say that he's an Injury prone player ans has not been consistent despite being a solid player for Barcelona.
Araujo should have been a done deal to another club right now but his Injury has made things difficult for Barcelona to profit from his sale.
Hansi Flick is a top quality manager, I don't deny his capabilities, but, he'll need players. Right now, take a good look at the Barcelona squad and you'll see that they lack a natural defensive midfielder. It'll be another difficult season. To shield the defense and avoid unnecessary bookings ( Yellow Card )
Has the move of Conor Gallagher to Atletico Madrid been finalized already? He is one hardworking player, I believe he'll successfully achieve all he wants in La Liga.