The deal is structured so that D'Amigo can play at either the NHL or minor-league level, the Sabres announced Thursday. The team had retained the player's rights by tendering him a qualifying offer last month.
D'Amigo was acquired by Buffalo in a trade that sent forward Luke Adam to Columbus in December 2014. D'Amigo was called up from the minors in March, and had no points in nine games with the Sabres.
Overall, he has a goal and three assists in 31 career NHL games since being selected in the sixth round of the 2009 draft by Toronto.