Mezue ahịrịokwu na-esonụ: N'oge 2015-16 oge, Cowen gbalịsiri ike ime ka onwe ya sie ike n'ime usoro Ottawa, mgbe ụfọdụ na-ahụ onwe ya dị mma. Na February 9, 2016, a gụnyere Cowen na ngọngọ, mgbanwe ndị egwuregwu itoolu na Toronto Maple Leafs. Cowen, Colin Greening, Milan Michalek,
E zigara Toronto na ntuli aka nke abụọ nke afọ 2017 iji gbanwere onyeisi ndị Maple Leafs Dion Phaneuf, Matt Frattin, Casey Bailey, Ryan Rupert na Cody Donaghey. N'abalị iri abụọ na isii nke ọnwa Febụwarị afọ 2016, ndị Maple Leafs tinyere Cowen na mgbaghara ma kenyezie ya na ndị otu AHL ha, ndị Toronto Marlies. Mgbe ahụ, Toronto zigara Cowen n'ụlọ ka ọ na-echere nzụta ma nye ya nnwere onwe ịkpọtụrụ ndị otu ndị ọzọ gbasara nkwekọrịta ọhụrụ maka oge 2016-17; ịzụta nkwekọrịta Cowen ga-enye ndị Leafs $ 650,000 ụgwọ akwụmụgwọ maka oge 2016-17.