Change is needed in every competition but I think Barcelona doesn't need to make changes for now because I think their squad is perfect enough to compete next season, Hansi Flick just needs to maintain what he did last season, but maybe the small shortcomings that need to be fixed are on the defense side because even though their defense is not bad sometimes the players like to make mistakes that result in defeat.
Btw I haven't heard the latest news regarding the purchase of Nico, has Barcelona not found common ground with Athletic Bilbao?
Both sides want to complete this transfer, and Nico also wants to join Barcelona. But the main issue is that Athletic Bilbao believes Barcelona will not be able to finalize this transfer because of their financial problems. The main reason is that Athletic Bilbao wants Barcelona to pay the entire transfer fee in a single payment. Obviously, since Barcelona is dealing with financial difficulties, they cannot make a one time payment, and are asking to split the transfer into several installments. As for the defense, I think the main problem was the goalkeeper last season. This issue will be solved, so I believe Barcelona's defense will become even stronger.
They have financial issue and that has limited them on buying some key players that would have made great impact in that team, we all saw how Nico connected really well in the national team and that's why the connection was indeed needed because he would really help boost the performance of the team but due to financial restraint they can't meet up with his signing but hopefully they sign him.