Senyshyn, a forward, was chosen by the Boston Bruins with the No. 15 pick in the 2015 NHL Draft, the last of three straight first-round picks by the Bruins. He signed a three-year contract with Boston on Nov. 12, 2015, after having 45 points (26 goals, 19 assists) for Sault Ste. Marie of the Ontario Hockey League. He returned to Sault Ste. Marie and scored 45 and 42 goals in the next two seasons.