After spending four seasons in the American Hockey League (AHL) with Toronto's farm team, Harrison made his NHL debut on January 27, 2006, against the Montreal Canadiens, in which he registered his first NHL career point, coming in the form of an assist.

[2] [3] On July 9, 2009, he signed a two-way contract with the Carolina Hurricanes that would pay him $500,000 in the NHL and $125,000 in the AHL.

[citation needed] During the 2014–15 season, Harrison was traded by the Hurricanes to the Winnipeg Jets in exchange for a 2015 NHL Entry Draft sixth round pick on December 18, 2014.

[5][6] In the following 2015–16 season, on the eve of opening night on October 6, 2015, Harrison cleared waivers, and was reassigned to the Manitoba Moose of the American Hockey League.

[7] In returning to the AHL for the first time since 2010, Harrison appeared in 18 games with the Moose before he was included in a trade deadline deal by the Jets, along with Andrew Ladd and Matt Fraser to the Chicago Blackhawks in exchange for Marko Daňo and a first-round pick in the 2016 NHL Entry Draft on February 25, 2016.