Prior to the 2015 NBA draft, Waldow worked out with a number of NBA teams including the Milwaukee Bucks. In August 2015, Waldow signed with the Antwerp Giants of the Belgian league. He was inside the Brussels airport at the time of the terror attacks of March 22, 2016. Waldow was scheduled to board a flight to Italy to play in the FIBA Europe Cup, but did not get on the plane due to the attacks. According to Waldow, he was inside the food court with a teammate when he heard screams and ran downstairs to meet with the rest of the team.