Xavi is about to lose his young player Gavi and there is the chance for another player to have the same situation or they even have to decrease their salaries because of the situation they have in Barcelona they cannot pay the salaries to some players, and their Messi can be a life saver however Messi will surely ask for high salary depending in his quality which can be challenging for Barcelona to hire this player.
I don't understand how anyone can still think, that there is even a minimal chance, that Lionel will come back to FC Barcelona. The only reason why he left Barca 2 years ago was the fact that Barca already was in big financial trouble back then and they simply could not afford to play the extremely high salary for him. He probably could have stayed at Barca back then if he would have been happy with a lower salary but he did not want to do that.
Now the financial situation of Barca is not better, maybe even worse than two years ago and i doubt that Messi will play for a salary that FC Barcelona could afford to pay. I think it should have the highest priority for Barca now to get rid of their huge debts even if it means that they have to sell a few good players.