The biggest transfer rumour this morning is that Serie A champions Juventus have tabled a huge bid for rival Napoli's star striker Gonzalo Huguain. The usually parsimonious club's mega offer for the Argentine has sparked excitement among Man United fans, who think this is a clear sign that their French midfielder Paul Pogba is leaving.

Real Madrid, Paris Saint-Germain and Manchester City are three of the richest clubs in world football. Their financial backing is unrivalled in the modern game and their ability to buy the best players in the world has given them the competitive edge over domestic rivals.