Rubuta ci gaba don wannan sakin layi - Horák ya fara aikinsa na sana'a tare da ƙungiyar garinsa HC České Budějovice na Czech Extraliga, yana bayyana a wasa ɗaya tare da kulob a 2007-08 da kuma takwas a 2008-09. New York Rangers sun zaba shi a zagaye na biyar, 127th gaba ɗaya, a cikin 2009 NHL Entry Draft
Ka yi haƙuri. Bugu da ƙari, Horák ya zaɓa ta kungiyar Western Hockey League (WHL) ta Chilliwack Bruins tare da na takwas na gaba ɗaya a cikin shirin shigo da Hockey League na Kanada (CHL). Kodayake yana da ƙarancin ilimin Ingilishi, Horák ya koma Kanada don shiga Bruins don kakar 2009/10 WHL.