Background
He is the son of former Alloa, Hamilton and Street Mirren defender Andy Millen.
He is the son of former Alloa, Hamilton and Street Mirren defender Andy Millen.
Millen has previously played for Dunfermline Athletic and Livingston. Millen made his Dunfermline debut against Hamilton on 2 February 2013, having played for the Dunfermline U20s team alongside team-mate Shaun Byrne. After the Pars went into administration, Millen featured regularly in the first-team, and scored his first goal for the club, a penalty, against Forfar in the First Division play-offs on 11 May 2013.
His other three goals all came from the penalty spot against Brechin, Forfar & Greenock.
After leaving Dunfermline at the end of the 2014-2015 season, Millen signed for Scottish Championship side Livingston in July 2015. Millen stayed with the side for only six months, leaving in January 2016 in order to seek regular first-team football.
Shortly after leaving Livingston, Millen signed a six-month contract with Clyde who he previously played for as a youth player.