Due to his ankle injury, teams were unwilling to give Prust a contract, with concerns continuing to be raised over his foot speed and ankle itself. Going unsigned for the duration of the summer, he agreed to sign a Professional Try Out contract with the Toronto Maple Leafs on August 22, 2016. Prust's main reason for signing the try out was to fulfil his childhood dream of playing for the Maple Leafs, the team he grew up cheering for. After an unremarkable training camp, along with stiff competition for role players on the Leafs roster, he was released by the team on October 11, 2016, He then embarked on his first overseas stint and European professional experience in late November 2016 after signing with the Thomas Sabo Ice Tigers of the German top-flight Deutsche Eishockey Liga (DEL). In the 2016-17 season, Prust added a needed physical presence to the Ice Tigers, contributing 8 points in 29 games with the team.