Pari gbolohun ti o tẹle: Walman ṣe ere hockey junior pẹlu awọn Toronto Jr. Canadiens ni Ontario Junior Hockey League (OJHL) ṣaaju ṣiṣe si hockey kọlẹji pẹlu Providence College ti Hockey East. Ṣaaju akoko akoko akọkọ rẹ pẹlu awọn Friars, Walman ni a yan ni
2014 NHL Entry Draft ni ìpele kẹta, 82nd lapapọ, nipasẹ St. Louis Blues.