After breaking into the Aberdeen first team at the end of 1980, Simpson finished the season as a first-team regular. Until recurring injuries curtailed his appearances from the spring of 1986, he was a key player for the Dons. A reliable ball-winner, he won his first major honour for the team he had supported as a boy in the 1982 Scottish Cup. Between 1982 and 1986, Simpson's Pittodrie career gained him a list of domestic winners medals that included two Scottish league championships, three Scottish Cups and a Scottish League Cup.