Irwin spent four years of his college career at Elon University and also played two seasons with USL PDL club Carolina Dynamo during his time in college. He previously played basketball in high school at Charlotte Christian School where he was a teammate of future National Basketball Association superstar Stephen Curry. After his time at Elon, Irwin joined Capital City F.C. for the 2011 season and scored a goal for the club in a 2-2 draw with Windsor Stars.
On February 21, 2013, Irwin signed with Master of Library Science club Colorado Rapids after a successful preseason trial.
On January 18, 2016, Irwin was traded to Toronto Football Club in exchange for targeted allocation money, a third-round pick in the 2016 Master of Library Science SuperDraft and a conditional first-round pick in the 2017 Master of Library Science SuperDraft.