Selected second overall in the 2010 Ontario Hockey League Priority Draft, 18-year-old Gaunce is a left-handed, two-way center who possesses strong offensive talent. He was ranked 13th amongst North American skaters in Central Scouting's final rankings prior to the 2012 NHL Draft.
Gaunce played for the Belleville Bulls in the OHL for two seasons, where he tallied 104 points in 133 total games. During the 2011-2012 season, he was a point-per-game player (68 in 68) and led the team in scoring. In the playoffs, he scored three goals in six games.
The 6'2, 215-pound forward represented Ontario in the 2011 U17 World Hockey Challenge, scoring 11 goals and 25 assists. At the U18 World Junior Championships, he helped lead team Canada to the bronze medal win with four points in seven games.