2009-10: Loic Leduc appeared in two midget major games – seeing limited ice time for Cheateauguay Patriotes – and played the bulk of the season for Patriotes in Midget Espoir in Beauharnois. He was selected by Cape Breton in the second round (23rd overall) of the 2010 QMJHL Entry Draft.
2010-11: Leduc skated in 36 games for Cape Breton in his first QMJHL season. He scored 1 goal with 3 assists and was minus-14 with 27 penalty minutes. The Screaming Eagles reached the playoffs despite finishing last in the Maritimes Division and winning just 18 games. Leduc skated in 2 of 4 games in Cape Breton's first round series with eventual champion Saint John and was minus-two with no points or penalty minutes.
2011-12: Leduc played in 65 of 68 games for Cape Breton in his second season. He was minus-3 with 2 goals and 8 assists and was third on the Screaming Eagles with 99 penalty minutes. Cape Breton finished fifth in the six-team Maritimes Division and once again ran into Memorial Cup-bound Saint John in the first round. In four playoff games Leduc was minus-nine with 1 assist and 4 penalty minutes. Leduc was ranked 209th amongst North American skaters in Central Scouting's final rankings and was selected by the Islanders in the fourth round (103rd overall) of the 2012 NHL Draft.
A towering blue liner, Leduc uses his entire 6'6 frame to his advantage. Surprisingly mobile for such a large player, Leduc is at his best when he is playing within his abilities and focusing on a simple, no nonsense, defense-first game. Not simply a physical force, Leduc is positionally strong and capable of playing plenty of minutes in a shutdown role.