20) Diego Forlan (Independiente to Manchester United – £6.9m – 2001)
This is definitely a case of ‘what might have been’, rather than the player’s ability being to blame for the failure of the move.
After joining United, Forlan started with an 18-game barren spell in front of goal. He went on to score only 17 in 97 appearances for United before leaving for Villarreal. He went on to win two European Golden Shoes and the 2010 World Cup Golden Boot.
