McDiarmid started his career in Scotland with Dundee and played for the Scottish League against in the Irish League in February 1902.[1] McDiarmid joined Tottenham Hotspur in 1906 and played for only one season with the club. His debut with Tottenham was a home match in the Southern League against West Ham United on 1 September 1906.[1] Spurs lost the game 2–1.[2] McDiarmid moved to Northampton Town where he spent four seasons.[1]