Manchester United manager Jose Mourinho has lamented the proliferation of "dangerous" large transfer fees in this summer's market.
Mourinho benefited from the largest transfer in history last season when United signed Paul Pogba for a record £89m fee.
That record could be left in the dust this summer if Real Madrid complete a reported £161m move for Monaco's teenage sensation Kylian Mbappe, or Paris Saint-Germain activate the £197m release clause in Neymar's Barcelona contract.
Yet the Portuguese coach, who has previously expressed surprise at the £50m paid by rivals Manchester City for English right-back Kyle Walker, said the issue is not the fees commanded by the world's very best but the big money spent on lesser talents.
"The problem is not what you pay for these kind of players," said Mourinho.
"I don't think the problem is what you pay for Pogba, I don't think the problem is going to pay crazy for Neymar.
"I think the problem is with the other group which is a big group because players like Pogba, there is one or two transfers [like that] per transfer window. The other ones are where you have 100 transfers [like that] and for that is the dangerous area of the market.
"We now speak about £30m, £40m, £50m in such an easy way. I don't think it will ever kill the big clubs because the big clubs will always have the potential and conditions to produce this kind of money and not to be in problems.
"I think some other clubs, there will be problems when they realise that the money that is coming in and is going out and I also think that the financial fair play authorities, they have big work to do."