Pedzisa mutsara unotevera: Munguva ye2010 playoffs, Gallagher akasarudzwa semutambi wechidiki wechirume wegore muguta rake rokumusha reDelta, British Columbia. Mukutarisira
2010 NHL Entry Draft, akanga rakava 152nd pakati North American skaters vanokodzera kusarudzwa neDare NHL Central Scouting Bureau. Gallagher akasarudzwa wechi147th chose neMontreal Canadiens. Achidzokera kuchikoro chechidiki mushure mekutanga kwake kwekudzidzira musasa neCanadiens, akanyora WHL basa rakakwirira muna 2010<unk>11. Musi waFebruary 28, 2011, akatumidzwa zita reWHL Player yeVhiki mushure mekunyora gumi mapoinzi (zvinangwa zvishanu uye zvishanu zvinobatsira) mumitambo mitatu. Muna Kurume 2011, Gallagher akaiswa parutivi nekukuvara kwemusoro, kwakagadziriswa mushure mekugamuchira kurova mumutambo wakanangana nePortland Winterhawks. Achironga wekutanga paGiants uye wechisere pakati pevose WHL scorers vane 91 mapoinzi pamusoro pemitambo makumi matanhatu nenomwe, akatumidzwa zita kuWHL West First All-Star Team. Zvinangwa zvake 44 zvaingova zvina zvinyadzi zveEvander Kane's single-season team record.