Born in South Shields,[1] Armstrong started his career at Nottingham Forest in graduating from their youth system in 1992.
He made his debut for the Lancashire club in the 5–1 win over Southend United on 31 December 1994, playing in place of the injured Chris Vinnicombe.
Armstrong scored twice during his spell at Forest with both goals coming in the League Cup in games against Walsall[3] and Cambridge United.
He played 29 times (scoring once against Rotherham United)[5] before moving on loan to Grimsby Town in a bid to regain match fitness after suffering an injury.
Although he arrived at the club as a midfielder, he made the majority of his appearances at left-back due to Jamie Victory's long-term injury problems.
[14] Armstrong went on to make 13 appearances for Forest Green but was unable to help his loan club avoid relegation.
[17] Armstrong made his debut against Altrincham in a league game on 8 October 2011 and also featured against Histon and Workington in his month with the Pilgrims.
In October 2011, Armstrong signed for Hucknall Town as a player-coach, linking up with manager Des Lyttle.
However defeats against Corby Town and Stalybridge Celtic caused friction and after just eight games in charge Armstrong quit as Eastwood boss in September 2011.
After leaving his post as player-coach at Hucknall Town, Armstrong became manager of Quorn in late March 2012.