Kammala jumla mai zuwa: MacKenzie ya fara aikinsa na matasa yana wasa a garinsu na Sudbury Wolves na Ontario Hockey League (OHL). Bayan kakar wasa ta biyu, inda ya kara yawan maki daga 20 zuwa 87, Atlanta Thrashers ta zaba shi a zagaye na biyar, 128 gaba daya, a 1999 National Hockey League (NHL).
daftarin shigarwa. A lokacinsa na ƙarshe, ya yi rajistar kwallaye 40 da maki 89 wanda ya jagoranci Wolves a maki kuma ya gama na shida a OHL. Ya kuma gama da kashi 67 cikin dari na cin nasara, ya lashe duka OHL da Canadian Hockey League (CHL) Face-off Awards.