2010-11: Samuel Morin skated for the Levis Commandeurs midget AAA team in Quebec. He had 12 assists and 40 penalty minutes in 36 games and in three playoff games had 1 assist with 12 penalty minutes. He represented Quebec in the 2011 Canada Winter Games and in six games had 1 assist and 14 penalty minutes. Morin was selected by Rimouski in the first round (seventh overall) of the 2011 QMJHL Entry Draft.
2011-12: Morin played 62 games for Rimouski and was named to the QJMJHL All-Rookie Team. He had 8 assists and was minus-two with 57 penalty minutes for the Oceanic. After finishing fourth in its division, Rimouski made an improbable run to the QMJHL Finals. Morin was out of the lineup at the beginning of the playoffs due to a late season injury. He played in 10 playoff games and was minus-two with 1 assist and 8 penalty minutes. Morin player for Canada Quebec in the 2012 U17 World Hockey Challenge and had 1 assist with 6 penalty minutes in five games.
2012-13: Morin showed some offensive elements to his game in his second season with Rimouski. He bounced back after missing a month due to an upper-body injury late in the season, re-joining the Oceanic for the QMJHL playoffs and skating for Canada at the 2013 U18 World Junior Championship. He scored 4 goals with 12 assists and was plus-10 in 46 games, and had a team-high 117 penalty minutes. In the six-game playoff series with Gatineau he had 1 goal with 6 assists and was minus-one with 16 penalty minutes. Morin was plus-six with 2 assists and 6 penalty minutes in seven games for Canada's gold medal-winning U18 team in Sochi, Russia. He was ranked 23rd amongst North American skaters in Central Scouting's final rankings prior to the 2013 NHL Draft.
A towering presence on the blue line, Morin plays plenty of minutes against the opposing team's top offensive units and is called upon to provide a steadying force in the defensive end. Physical in his own end, Morin doesn't always make the most of his big frame, although he still needs to continue to fill out. He makes smart plays defensively and good first passes out of the zone. He also has a booming slapshot, but his overall offensive game still needs refinement. With a long stride, Morin is a powerful skater, but will need to continue to improve as he adds muscle to his frame.