 He debuted on the opening day of 2010–11 in a 1–0 defeat at home to Grimsby Town and scored his first goal for Crawley ten days later with the second goal in a 2–1 win over newly promoted Bath City.McAllister went on to score two goals in the following match, a 3–0 victory away to Hayes & Yeading United.He started in Crawley's FA Cup fifth-round tie against Manchester United at Old Trafford on 19 February 2011, which finished as a 1–0 defeat.