Just stop inventing calamitous scenarios.
Why would Messi blow our budget?
His salary is £64m a season. We already know sponsors have been lined up to cover costs, just like Juventus did with Ronaldo.
We already know the club is looking for a new main sponsor.
We know Messi is going to bring a ton of money with him, from shirt sales, new fans, existing endorsements.
We know Khaldoon isn't likely to make a bad financial decision, based on his running of the club for the past 10 years.
You're working yourself into this panic over absolutely nothing. We're going to fix our existing issues, get Koulibaly, maybe Aouar, maybe a LB, and then anything to do with Messi will be on top of all that.