1 Juan Mata
Cost: 37.1 million pounds
From: Chelsea

2 Dimitar Berbatov
Cost: 30.7million pounds
From: Tottenham Hotspur
Year: 2008
Impact: The striker from Bulgaria displayed moments of magic at Old Trafford but could not to cement a first team place and was eventually packed off to Fulham last season.

3 Rio Ferdinand
Cost: 29.3million pounds
From: Leeds United
Year: 2002
Impact: Ferdinand has been United’s defensive mainstay since his arrival in July 2002. However, the England international may leave as a free agent at the end of the current season.