Sproule, a winger who was known for his explosive pace, played in the Irish Football League for semi-professional clubs Omagh Town and Institute. He combined playing football with his full-time career as an engineer. Scottish Premier League club Hibernian invited him for a trial in January 2005, after he had been transfer listed by Institute. He impressed manager Tony Mowbray and signed as a full-time professional until the end of the season, which meant that he had to give up his day job as a fabrication engineer. Hibs paid Institute a transfer fee of £5,000.