Douglas, Lanarkshire born left back Jock MacKenzie began his football career with Glenbuck Cherrypickers and first moved to English football with North Eastern League club Carlisle United in 1909. He joined Southern League club Norwich City in 1910, soon becoming a virtual ever present in The Canaries’ first team, becoming club captain. He made 158 League and Cup appearances for the club in the time leading up the 1914-15 season, including a run of 90 consecutive matches between December 1911 and January 1914. MacKenzie ultimately became the first Norwich player to appear in over 200 games for the club and his final tally of games played for Norwich, 204, is a club record – the highest total appearances by any Norwich City player in non league matches.
However the suspension of peacetime football in England due to the onset of the First World War saw MacKenzie return to Scottish football in the 1915 close season, where he joined Heart of Midlothian in August 1915. He made his Scottish League debut in a win over Hamilton Academical towards the end of the same month, and played 25 matches for The Jambos during 1915-16 before being called up for military service. MacKenzie served as a gunner in the Royal Garrison Artillery during the First World War. serving in Africa.
After the War MacKenzie had a trial with Millwall before signing for Birmingham & District League club Walsall. When Walsall became a founding member of the Third Division (North) in 1921, MacKenzie made his Football League debut in their first Third Division match, a defeat at Lincoln City in August, and played 3 further matches before Christmas before retiring from football in 1922.