 McChrystal began his career at Wolverhampton Wanderers where he was one of a plethora of young players from Northern Ireland playing there.After spending three years at Molineux, including a spell on loan at Bradford City in 2003, he was released by the Midlands club and he eventually returned home to sign for his local team Derry City of the League of Ireland in April 2003, despite interest from other English clubs.He was then loaned out to near neighbours Institute by Dermot Keely on a three-month deal.