He was loaned by the Blackhawks to Canada's 2021 World Junior Ice Hockey Championships roster, where he was eventually named captain. On December 23, in Canada's lone pre tournament game which was played against Russia, Dach bumped into Russian forward Ilya Safonov. The impact was enough to injure Dach, who left the game immediately and did not return. X-rays later confirmed Dach had sustained a fracture in his wrist, and would miss the rest of the tournament.