Deslauriers remained in Buffalo during the 2014 offseason where he lost nearly 20 pounds. During the pre-season, he skated alongside Sam Reinhart and was worked into a checking role with Cody McCormick and Patrick Kaleta. Having formally played as a defenseman, the 2014–15 season became Deslauriers' first as a winger. When speaking on the change, he said he felt better playing on the wing but would change positions if needed. He finished the season playing in all 82 games and tallying 15 points and 71 penalty minutes. He also finished ninth in the league with 261 hits. As a result of his play, Deslauriers was voted the teams' Rookie of the Year.
