La Liga president Javier Tebas has indicated he will report PSG over the deal, while Barcelona president Josep Maria Bartomeu said it would be impossible for a club to buy Neymar without contravening FFP rules.
PSG - owned by Qatar Sports Investments - were hit with a €60m fine over FFP breaches in 2014 and UEFA said it will take a close look if the Ligue 1 side complete a deal for Neymar, although no complaints have yet been received.
UEFA's chief executive director for financial and sustainability Andrea Traverso told Spanish news agency EFE: "PSG have to respect FFP rules like any other club in Europe. They have to prove that they have no losses of more than €30m within three years.
"The potential impact of Neymar's signing with PSG would affect the economy of the club for many years. It is very difficult to judge this kind of transfer in advance because we do not know the plans of the French club. They could sell some players for a similar or higher price. Only afterwards can we make a calculation and make sure the rules are met.
"Regardless of whether we receive a complaint or not, we will discuss the details of the transfer in any case in order to ensure FFP rules are respected. Previous cases are taken into account if a potential sanction is decided, but now there is no open case and there is no reason to speculate on any hypothetical outcomes.
"Clubs are keenly aware of the rules. The fact that the debts of European clubs have dropped from €1.7 billion in 2011 to less than €300m now shows that the rule has had a positive impact on the stability and sustainability of European football."