Career
He was drafted in the first round, 30th overall, in the 2009 National Hockey League Entry Draft by the Pittsburgh Penguins. Amateur
Després began his major junior ice hockey career with the Quebec Major Junior Hockey League (QMJHL)"s Saint John Sea Dogs, who acquired Després with the first overall selection at the 2007 QMJHL Entry Draft. He scored his first QMJHL goal on September 23, 2007, against the Lewiston Maineiacs.
After two seasons of play, Després was rated as the top professional prospect in the QMJHL by several scouting bureaus and media outlets in anticipation of the 2009 National Hockey League Entry Draft (June 26–27 in Montreal).
Remaining with Saint John for the 2009-2010 season, Després appeared in 63 games, scoring nine goals and 47 points, as the Sea Dogs had a League-best 109 points. He helped the Sea Dogs reach the President"s Cup finals, though Saint John lost to the Moncton Wildcats in six games.
In 21 playoff games, he had two goals and 19 points. In 2010-2011, Després was limited to 47 games, but increased his goal scoring output to 13 goals, on his way to recording 41 points and winning the Emile Bouchard Trophy as the QMJHL"s best defenceman.
Professional
Després played his first career National Hockey League game on December 1, 2011, with the Penguins against the Washington Capitals.
He earned his first National Hockey League point on an assist on Chris Kunitz"s goal. He also posted a +2 plus-minus rating on the night. Després" scored his first career National Hockey League goal on December 17, 2011, against Ryan Miller of the Buffalo Sabres.
On March 2, 2015, Després was traded to the Anaheim Ducks in exchange for defenceman Ben Lovejoy.