 Fleck began his career in the Rangers youth teams; he played in their 5–0 Scottish Youth Cup victory over Celtic on 26 April 2007.On 12 July 2007, Fleck was called up to take part in the full squad pre-season tour of Germany, and was handed his debut for the first team against SV Lippstadt 08 on 15 July 2007, becoming the first 15-year-old to play for the first team since Derek Ferguson in 1982.Fleck impressed and scored in a 3–1 friendly victory over Sportfreunde Lotte in the next friendly game.