Junior After a season of
AAA midget with the Windsor Jr. Spitfires, Kassian debuted at the
major junior level with the
Peterborough Petes in
2007–08. Playing in his first career OHL game, he recorded two assists against the
Sudbury Wolves on September 20, 2007. He scored his first OHL goal the following month against the
Erie Otters on October 11. Lastly, he competed in the 2009
CHL Top Prospects Game for Team
Cherry, a contest in which he injured
John Tavares with a
hit. Leading up to the
2009 NHL entry draft, Kassian was ranked 10th among eligible prospects playing in North America (not including goaltenders) by the
NHL Central Scouting Bureau (CSB). Chris Edwards of the CSB heralded him as "one of the toughest guys in the OHL and probably the entire draft", while also highlighting his "play-making and puck-handling abilities". Back with the Petes, Kassian was chosen to replace the departed Zach Harnden as
team captain after Harnden starting playing with the Kingston Frontenacs. Thirty-three games into his
2009–10 OHL season, Kassian was traded to the
Windsor Spitfires. Before the trade, Kassian had been suspended one game by his team for breaking curfew. Limited to 38 games between Peterborough and Windsor due to the ban, Kassian totalled 12 goals and 31 points. Returning from the suspension in time for the 2010 playoffs, he added 7 goals and 16 points over 19 games to help Windsor to a
J. Ross Robertson Cup as OHL champions. The win qualified Windsor for the
2010 Memorial Cup, Canada's national major junior championship, which they won as well. Defeating the
Brandon Wheat Kings in the final 9–1, Kassian had a goal and an assist in the championship-winning game. Following the Memorial Cup win, Kassian was arrested after an altercation at a bar in Downtown Windsor on May 30, 2010. Charged with assault, he reached an agreement several months later, in October 2010. The charge was dropped in exchange for 25 hours of community service, a $500 donation to charity, and payment for the victim's dental work. Had he been convicted, Kassian would have been ineligible to cross the border into the United States, which would have conflicted with his hockey career. Kassian returned to the Sabres' training camp in September 2010. While he was sent back to junior for the second straight year, he remained on the team's pre-season roster as one of the final cuts in October. During Game 4 of the Conference Finals against the
Owen Sound Attack, Kassian received a match penalty for a hit on opposing defenceman
Jesse Blacker, which was ruled as "intent to injure". Following the contest, the penalty was supplemented with an additional three-game suspension, sidelining him for the remainder of the series. Out of the lineup for Game 5, he only needed to serve half of the total suspension as the Attack eliminated the Spitfires four-games-to-one.
National Hockey League Buffalo Sabres in February 2012 With his junior season over, Kassian was assigned by the Sabres to their
American Hockey League (AHL) affiliate, the
Portland Pirates, for their
Calder Cup playoffs on April 29, 2011. The following night, he made his AHL debut in Game 3 of the Atlantic Division Finals against the
Binghamton Senators. Kassian remained with the Sabres for a month and a half in his initial NHL stint before being reassigned to Rochester. Analysts from
TSN and
The Vancouver Sun also echoed the sentiment, commenting that while the Canucks gained elements in Kassian that were required to succeed in the playoffs, Hodgson's skill set reflected the style of play that Vancouver's success was based upon. In a telephone interview with Andrew Greven of TSN shortly after the trade, Kassian said he was surprised at the trade but was excited to play for a
Stanley Cup-contending team. The reaction in the Vancouver media was largely of surprise that Gillis would trade away a well-performing rookie for one that was unproven at the NHL level.
The Vancouver Sun columnist Iain MacIntyre declared it "a stunner" and "one of the most unpopular trades in Vancouver in years." Another
Sun article likened the deal to a lopsided 1996 trade between the Canucks and
Pittsburgh Penguins in which two first-round prospects of opposite playing styles – the skilled
Markus Näslund and the larger, more aggressive
Alek Stojanov – were exchanged. Kassian made his Canucks debut the night after the trade, registering a shot on goal and 12 minutes and 27 seconds of ice time in a 2–1 shootout loss to the
Phoenix Coyotes. Kassian scored a goal and an assist, his first of each with the Canucks, in a game against the Sabres on March 3, his third game with the Canucks. The following game, against the
Dallas Stars, Kassian was called to take a
penalty shot 24 seconds after the opening faceoff, making it the second-fastest penalty shot to be called in NHL history (after
Maurice Richard took a penalty shot 12 seconds into a game against the
Chicago Blackhawks). He missed against goaltender
Richard Bachman while attempting a backhand deke. On July 3, 2014, Kassian signed a two-year contract extension with the Canucks worth $3.5 million.
Trade to Montreal On July 1, 2015, Kassian and a 5th-round selection in the
2016 NHL entry draft were traded to the
Montreal Canadiens in exchange for
Brandon Prust. On October 4, he was involved in a car accident on a non-practice day, suffering a broken nose and a fractured left foot. Kassian was not the driver of the car, however he was under the influence. This resulted in Kassian being suspended without pay and sent to the NHL's substance abuse program. On December 15, after completing the substance abuse program, the NHL announced Kassian's return from suspension. However, only a few hours after the announcement, the Canadiens put him on waivers. On December 26, Kassian was told to not report to the
St. John's IceCaps by the
Montreal Canadiens.
Edmonton Oilers On December 28, 2015, Kassian was traded from the
Montreal Canadiens to the
Edmonton Oilers for goaltender
Ben Scrivens. Kassian scored his first goal as an Oiler against the
Tampa Bay Lightning on the road on January 19, 2016. On June 26, 2017, Kassian signed a three-year deal worth a reported $5.85 million. On January 29, 2020, Kassian signed a four-year contract extension worth $12.8 million with an annual salary of $3.2 million. On February 14, 2020, NHL's Department of Player Safety announced Kassian had been suspended for seven games for kicking
Erik Černák of the
Tampa Bay Lightning, and had to forfeit $166,463.43 in salary. The suspension was the fourth of Kassian's NHL career and came one month after he was suspended two games for an altercation with
Calgary Flames player
Matthew Tkachuk, for violating rule 46.2 of the NHL rule book as an aggressor when he dropped his gloves.
Arizona Coyotes On July 7, 2022, Kassian was sent to the
Arizona Coyotes along with Edmonton's first-round pick (29th overall) in the
2022 NHL entry draft, a second-round pick in 2024, and a third-round pick in 2025, in exchange for Arizona's 32nd overall pick in the 2022 Draft. In the following
2022–23 season, Kassian was primarily used in a fourth-line checking role, posting a career-low two points through 51 regular season games. On June 20, 2023, Kassian was placed on unconditional waivers by the Coyotes and was bought out from the remaining year of his contract and released to become a free agent the following day.
Retirement from NHL On September 1, 2023, Kassian accepted an invitation to attend the
Anaheim Ducks' 2023 training camp on a
professional tryout contract (PTO). On October 8, the Ducks released Kassian from his professional tryout contract, and on October 26, Kassian announced his retirement from NHL play after 12 seasons.
Sparta Praha On January 28, 2024, Kassian was signed by
HC Sparta Praha of the
Czech Extraliga (ELH) for the remainder of
2023–24 season. ==International play==