|Date of birth||23 July 1976|
|Place of birth||Birkenhead, England|
|Height||5 ft 11 in (1.80 m)|
|2002–2003||Kansas City Wizards||55||(5)|
|* Senior club appearances and goals counted for the domestic league only and correct as of 3 June 2011
College and Amateur
Armstrong was born in Birkenhead, England and raised in Cape Town, South Africa. He came to the United States to attend Butler University in Indiana and finished as the school's third all-time leading scorer with 43 goals and 16 assists. During his college career Armstrong also played for the Mid-Michigan Bucks in the Premier Development League.
Armstrong began his professional career in Sweden with Västra Frölunda IF before moving to English First Division side Watford on a free transfer in October 2000. He made three appearances for the club, all as a substitute, before being released at the end of the 2000–01 season.
He was selected in the second round – 13th overall – of the 2000 MLS SuperDraft by D.C. United. Armstrong was traded to Kansas City for Brandon Prideaux on 11 January 2002. He spent two years with the Wizards, appearing in regular season and playoff each year.
Armstrong missed the 2004 Major League Soccer season while recovering from ACL surgery on his right knee. He joined the Columbus Crew in 2005. At the beginning of the 2006 season Armstrong signed with A-League club Charleston Battery, where he would spend the remainder of his outdoor career, and served as an assistant coach during his final season with the club. Armstrong continues to live the Charleston area, and is currently the broadcast color commentator for the Battery.
- 2006–2007 MISL Rookie of the Year