#2 Owen Hargreaves
Sir Alex signed him from FC Barcelona for £17m in 2007 even though he had spent most of the season on bench due to a fractured leg.
His first season proved that Ferguson had made a good move due to his decent performances but the plethora of injuries to Owen soon turned out to be his nemesis.
Succession of injuries led him to have operations on both his knees and this made him miss out majority of the matches during his time at Manchester United. He failed to impress during his three comeback attempts and was never really in favor during the later stages of his career at United.
His dismal fitness records forced United to release him and he later went on to join City before retiring at the age of 31 due to prolonged injuries.
He is fondly remembered for the match winning free kick against Arsenal.