A defenseman during his four seasons in the Quebec Major Junior Hockey League and his first two pro seasons, Deslauriers was converted to left wing in 2013 while with Manchester of the American Hockey League.

Deslauriers, a third-round pick (No. 84) of the Los Angeles Kings in the 2009 NHL Draft, played in the QMJHL with Rouyn-Noranda from 2007-10 and with Gatineau in 2010-11. He led Rouyin-Noranda defensemen with 36 assists in 2009-10, and the next season topped Gatineau defensemen in goals (13), assists (30), points (43), power-play goals (six) and plus-minus rating (plus-22).

Deslauriers got his first points as a professional with two assists Dec. 3, 2011 against Providence and scored his first AHL goal against Portland on Jan. 15, 2012. In 2012-13 he led Manchester with two goals and four points in four games during the 2013 Calder Cup Eastern Conference Quarterfinals.

Deslauriers made the switch to left wing to begin the 2013-14 AHL season. He had a six-game point streak from Jan. 25-Feb. 8, 2014, and was leading Manchester in goals (18) and second (39) in points (39) when the Kings traded him to the Buffalo Sabres on March 5, 2014. The Sabres also got Hudson Fasching in the trade and received Brayden McNabb, Jonathan Parker, and a second-round draft picks in both 2014 and 2015.

He made his NHL debut March 7, 2014, for Buffalo against the Florida Panthers and had four shots and four hits in 15:08 of ice time. Deslauriers scored his first NHL goal April 4, 2014, against the Detroit Red Wings at Joe Louis Arena. Assigned to Rochester to finish the season, he finished third in the AHL with 230 shots.

Deslauriers was the only Sabre to appear in all 82 games in 2014-15 and had his first multipoint game in the NHL with a goal and an assist Dec. 27, 2014, against the New York Islanders.