In March 1984, Dario Gradi signed Thomas for Crewe Alexandra, on a free transfer. After three substitute appearances, Thomas made his full debut on 28 April 1984 in a 3–0 home win over Tranmere Rovers, and marked the occasion with his first goal for the club. A tough-tackling player, who could operate in central midfield or out on the right, Thomas was a mainstay of the team as Crewe finishing mid-table in the Fourth Division. He was to spend two-and-a-half seasons at Gresty Road, playing 137 times for the club