What is Balague basing that on?
Wages might be an issue, but Mascherano is leaving and so is Arda. Both earn a significant amount of money. Then a few others like Gomes and possibly Denis are going to leave too. There will be room to include both Griezmann and Coutinho's wages.
I think we'll end up signing four players. One forward, two midfielders and one CB. If Vermaelen manage to stay injury free and is okay with being a 4th/borderline 3rd option then perhaps we should keep him. Good to have some experience at the back and he's not on high wages either.
We're going to earn more than 70m in our new Nike Sponsorship deal kicking in from next year too. That's on top of the current deal so 70m+ in extra income.