He also played in the American Hockey League (AHL) for Columbus' and Atlanta's farm teams, the Syracuse Crunch and Chicago Wolves respectively.

MacKenzie's father Ken is the assistant general manager of the Ontario Hockey League's Sudbury Wolves.

MacKenzie began his junior career playing for his hometown Sudbury Wolves of the Ontario Hockey League (OHL).

[1][2] Following his final season with Sudbury, MacKenzie joined the Thrashers' American Hockey League (AHL) affiliate, the Chicago Wolves.

[1][5] In the opening minutes of his first home game as captain, MacKenzie crashed into the opposing team's net and broke his ankle.

He made his Blue Jackets debut on December 10, 2007, against the Anaheim Ducks; he was reassigned to Syracuse the following day.

[13] Later in the season, he was re-called and scored his first career NHL goal against Mike Smith in a game against the Tampa Bay Lightning.

[5] He established himself as an NHL regular in 2010–11 and finished the season with career highs in goals (9), assists (14), points (23) and plus-minus rating.

[16] After establishing himself, MacKenzie became a fixture on the Blue Jackets' fourth line and an integral part of their penalty kill.

[16] After passing an off-season physical, due to concussion concerns, Columbus re-signed MacKenzie to a two-year deal.

[20] After playing only one game that season, he retired in the offseason and was named an assistant coach for the Panthers on June 4, 2019.