A product of the Manchester United academy, during his development Simpson played on loan for Sunderland, Ipswich Town and Blackburn Rovers in England, and Royal Antwerp in Belgium.
Akiwa bidhaa ya akademi ya Manchester United, wakati wa maendeleo yake Simpson alicheza kwa mkopo katika klabu za Sunderland, Ipswich Town na Blackburn Rovers za Uingereza, na Royal Antwerp nchini Ubelgiji.