2007-08: Zachary Yuen was chosen in the first round, 22nd overall, of the 2008 WHL Bantam Draft by the Tri-City Americans.
2008-09: Yuen spent most of the season with the Greater Vancouver Canadiens of the BCMML. In 35 games, Yuen scored 6 goals and added 13 assists for 19 points to go along with 60 penalty minutes. In 6 playoff games, Yuen registered 3 assists. Yuen saw his first WHL action with the Americans, registering no points in 4 games. In 7 playoff games for the Americans, Yuen scored 1 goal.
2009-10: In his WHL rookie season, Yuen played in 42 games for the Americans. He scored 1 goal and added 3 assists for 4 points. In 22 playoff games, Yuen scored 1 goal and added 1 assist for 2 points. Yuen played for Team Pacific at the 2010 World U-17 hockey Challenge, picking up 1 assist in 5 games.
2010-11: In 72 games for the Americans, Yuen scored 8 goals and added 24 assists for 32 points to go along with 65 penalty minutes. In 10 playoff games, Yuen registered 3 assists.
2011-12: Yuen returned to Tri-City for his third season in the WHL after attending training camp with the Jets. He skated in 66 games for the Americans and led all Tri-City defensemen with 38 points; scoring 12 goals with 26 assists. Yuen had a plus-45 plus/minus (tied with Brendan Shinnimin for tops on the team) and had 46 penalty minutes. Tri-City reached the Western Conference finals after finishing first in the U.S. Division. Yuen scored 1 goal with 4 assists and was minus-three with 18 penalty minutes in the playoffs.
Yuen is likely in his final year of junior hockey before he turns pro in 2013-14.