Some clubs have managed the transfer market especially well in recent years (Real Madrid, Manchester City and Liverpool have led the way), while others have struggled to match up (namely Barcelona, Manchester United and Chelsea.) But sometimes there is little they can do, as it is the players who hold the power.
July 1 marks the moment when stars including Tottenham striker Harry Kane, Man United forward Marcus Rashford and Paris Saint-Germain's Kylian Mbappe get to take control, as they will have 12 months left on their contracts.