2009-10: MacKenzie MacEachern played high school hockey as a sophomore at Michigan's Brother Rice HS in Bloomington Hills.
2010-11: MacEachern had a breakout season as a junior for Brother Rice. In 30 games he scored 34 goals with 36 assists and had 18 penalty minutes. Brother Rice reached the Division 2 finals and MacEachern was named co-MVP of the Michigan Interscholastic Hockey League.
2011-12: MacEachern spurned offers to play in the North American Hockey League to play for Brother Rice in his senior season and was named Michigan's Mr. Hockey. MacEachern was the leading scorer in Michigan high school hockey as Brother Rice won the Division 2 state championship. He committed to playing college hockey at Michigan State in 2013-14 and was selected to Team Michigan for the Minnesota NIT tournament. In 29 games for Brother Rice, MacEachern scored 42 goals with 48 assists and was plus-50. In four games at the Minnesota NIT he scored 3 goals with 4 assists and Team Michigan defeated Team Minnesota U18 in the championship game. The Chicago Steel selected MacEachern with the fourth overall pick in the 2012 USHL Entry Draft. Ranked 138th amongst North American skaters in Central Scouting's final rankings prior to the 2012 NHL Draft, he was selected by St. Louis in the third round (67th overall) of the 2012 NHL Draft.
2012-13: MacEachern played 50 games for the USHL's Chicago Steel, missing time with concussion-like symptoms in November and December. He scored 8 goals with 13 assists and was -11 with 35 penalty minutes. The Steel missed the USHL playoffs, finishing fifth in the Eastern Conference.
MacEachern is a combination of size, speed and skill. He has good vision and hockey sense which makes teammates around him better. His big body and long reach help him protect the puck and create space down low. The playmaking winger has good puck handling skills, soft hands and explosive acceleration to burst through the openings. He possesses excellent hand/eye coordination and athleticism that helps him create plays from out of nowhere. The potential top-six power forward still needs to improve his defensive game and gain more strength to be a force at the NHL level.
MacEachern had a solid rookie season in 2013-14, playing for the Chicago Steele of the USHL. He has most recently expressed his commitment to the Michigan State Spartans, ensuring at least four years of development time at the NCAA level.