2006-07: Kevin Marshall was a key force in helping Lewiston capture the QMJHL title in 2006-07. He posted a very respectable 32 points in 70 games (5 goals, 27 assists) this year for the MAINEiacs, to go along with a team-leading 141 PIMs.
2007-08: In his third year with the Lewiston MAINEiacs (QMJHL), Marshall put up a season-high 35 points (11g+24a) in 66 games. He added a goal and an assist in six playoff appearances with the club. He was named to the QMJHL Second All-Star Team before being traded to the Quebec Remparts at the close of the season.
2008-09: Marshall skated for Quebec (QMJHL) after three seasons with Lewiston and continued to display a combination of toughness and offensive opportunism. Marshalll was the second-leading scorer amongst Remparts defensemen with 9 goals and 29 assists, scoring 7 of his 9 goals on the power play, and led the team with 125 PMs in 61 games. He was +23 on a Quebec team that had the league's third best record and finished first in the East Division. In 17 playoff games he scored 1 goal with 10 assists and was -10 with 32 PMs.
2009-10: Marshall made steady progress with AHL Adirondack in his first pro season. He scored 2 goals with 7 assists and 80 PMs and was -8 for a Phantoms team that finished last in the AHL's East Division.
2010-11: Marshall led Adirondack defensemen with 120 PMs and appeared in 78 of 80 games for the Phantoms in his second pro season. He scored 3 goals with 11 assists and was -9 as Adirondack finished seventh in the East Division and failed to reach the playoffs.
2011-12: Marshall made his NHL debut with the Flyers at the end of November — one of several young defensemen pressed into service by Philadelphia due to a rash of injuries. He skated in ten games for the Flyers and was minus-one with 8 penalty minutes; averaging 8:45 minutes of ice time. Marshall spent most of the season in the AHL, first with Flyers' affiliate Adirondack and then Caps' affiliate Hershey after being optioned in a February 2012 trade. In 63 AHL games between the two clubs he was minus-six with 2 goals and 4 assists; amassing 116 penalty minutes. In the Bears' first round playoff series with Scranton/Wilkes-Barre he was an even plus/minus with 2 assists and 10 penalty minutes in five games. Marshall was re-signed as a restricted free agent to a one-year contract by the Capitals in July, 2012.
Marshall is regarded as a hard-working, stay-at-home defenseman who plays with a physical edge. He skates very well, has excellent balance and moves the puck efficiently.
Marshall was acquired from the Washington Capitals by the Toronto Maple Leafs in March of 2013.