Kammala jumla mai zuwa: Nemisz ya shiga OHL's Windsor Spitfires a 2006<unk>07, yana yin rikodin maki 34 a wasanni 62. Ya inganta zuwa maki 67 a wasanni 68 tare da Spitfires a shekara mai zuwa, yana samun kyautar ƙungiyar don sadaukarwa da ƙuduri. Lokacinsa ya jagoranci Calgary Flames don zaɓar shi tare da zaɓaɓɓen zagayen farko, 25th gaba ɗaya, a gasar
2008 NHL Entry Draft, wanda ya tsara shi ya zama mai karfi. Nemisz ya kafa aikinsa tare da Spitfires a 2008-09, inda ya zira kwallaye 36 da maki 77 a wasanni 65, yayin da ya kara maki 20 a wasanni 20 yayin da ya taimaka wa tawagarsa ta kama J. Ross Robertson Cup a matsayin zakarun OHL. Daga nan sai ya ci gaba da zira kwallaye guda shida a gasar Memorial Cup ta 2009 yayin da Spitfires suka ci Kelowna Rockets na Yammacin Hockey League don lashe gasar zakarun kasa.