4) Juan Mata – £37.1m
Mata cost a lot of money, but no United fans have complained yet. While his start at Old Trafford was slow, mainly because he was asked to play on the right wing – he slowly began to show his ludicrous ability towards the end of the season. Mata thrived in a more central role, and the only task Louis van Gaal has is how to field the Spaniard and Wayne Rooney in the same side.