Both Messi and Neymar are always looking for money, they don't care about their previous teams that make them to reach to their current position, only Ronaldo is still want to play in his old team.
Xavi is nothing to worry, they have Joao Felix that can replace Lewandowski and sooner or later the young star e.g. Vitor Roque will become a striker in Barcelona.
Barcelona is also experiencing a financial crisis so it is impossible to return Messi or Neymar to his old club, Barcelona will not be able to afford on the one hand their salaries are small there and they are old, what to expect in these two former Barcelona players who will soon retire.
Ronaldo had a conflict with Manchester United so he was dropped from the squad. But he seems happy now to be in the Arab League with a lot of money. LOL
Joao Felix is a loan player, if Atletico Madrid put a high price tag it seems Barcelona will not dare to take it, just rely on young players from the academy, but now they are not in a player crisis so stay relaxed for Xavi.