Ferguson believes that French side Paris St Germain's signing of Moura in a €45million deal is further evidence of the transfer market spiralling out of control.

Ferguson said: "I find it quite amazing that a club can pay €45million for a 19-year-old boy."

Ferguson continued: "To make a mark on everyone - to tell everyone that PSG are here - they have signed Thiago Silva from Milan and Zlatan Ibrahimovic.

"They must have spent about £150m in the last month. As you know, the only deterrent to that is UEFA.

"In the conditions of European football, you don't qualify for Europe by winning the league or coming second - you only get in by invitation.

"That's where, hopefully, UEFA can have some power. When somebody's paying £45m for a 19-year-old boy you have to say the game's gone mad."