 A member of Ayr United's football academy, Armstrong made his first team debut in the Scottish Second Division as a substitute on 7 May 2011 against Brechin City at Glebe Park.Ayr United won promotion via the play offs and he made his Scottish First Division debut on the opening day of the 2011–12 season.Armstrong moved into Junior football with Troon to gain experience of regular first-team football after a long education with Ayr United.