Mezue ahịrịokwu na-esonụ: Harrison bụ onye Toronto Maple Leafs wepụtara na agba nke atọ, nke 82 n'ozuzu, nke
2001 NHL Entry Draft. Mgbe o jesịrị oge anọ na American Hockey League (AHL) na ndị ọrụ ugbo nke Toronto, Harrison mere NHL mbụ ya na Jenụwarị 27, 2006, megide Montreal Canadiens, nke ọ debanyere aha mbụ ya na ọrụ NHL, na-abịa n'ụdị enyemaka. Na June 16, 2008, Harrison bịanyere aka na nkwekọrịta otu afọ na EV Zug nke Switzerland National League A, mana na Machị 27, 2009, ọ laghachiri na Toronto Maple Leafs, na-abịanye aka na nkwekọrịta, pro-rated na $ 475,000, iji kpọọ oge fọdụrụ na 2008-09.