2005-2006: In his fourth season Aaron led the team in scoring for the second consecutive year. He racked up a season total of 24 goals and 21 assists for 45 points in 62 games. Aaron missed 10 games due to injury. Aaron had six-game point streak, three goals and four assists, from January 23 to February 3. This streak tied ones by Thomas Hickey, Kyle Pess and Tyler Johnson. In 14 games in February Aaron had 15 points on nine goals and six assists. In the final game of the season against the Portland Winter Hawks Aaron scored a season high of four points, on two goals and two assists.
2004-05:In his third season Aaron played in all 72 regular season games and was the T-Birds leading scorer. He had 31 goals and 34 assists for 65 points. His 34 assists tied him with Chris Durand for the team lead. Ten of Aaron?s goals were power-play goals and he finished the season with a plus-28 on the ice. He had one short-handed goal. Aaron scored three goals in one game on two occasions, October 15th against Kelowna and December 4th at Tri-Cities. From December 11th through the 31st he had an eight-game point streak scoring four goals and getting seven assists. He also had a five-game goal streak from October 29th to November 10th. Aaron showed incredible improvement from last year by almost doubling his total points and bringing his plus/minus up by 10. Aaron?s talent was visible in the playoffs where he played in all 12 games and had 9 points on four goals and five assists.
2003-04: In his second season with the Thunderbirds Aaron played 63 games and had 21 goals and 15 assists for 36 points. Aaron led the team in plus/minus with a plus-18 and had 29 penalty minutes. Aaron had one game-winning goal, at Everett on December 13, and two power-play goals. He scored two goals in a game three times this season with two goals at Everett on November 1, against Spokane on December 30 and against Vancouver on February 28. Aaron had two assists in a game twice with two helpers at Everett on January 28 and at Spokane on February 13. His longest point streak during the season was a four-game point streak from February 27 to March 5. He also had a three-game point streak. Aaron also had a two-game goal streak. Aaron twice scored a goal at the end of the game with the goalie pulled. He did it at Everett on November 1 at 19:54 of the third period and at Portland on February 27 at 19:22 of the third period.
2002-03: In his rookie season with the Thunderbirds Gagnon played in 60 games and had 18 points on five goals and 13 assists. He only had 14 minutes in penalties and was a plus-1. Gagnon had the game-winning goal in a 6-3 victory against Kamloops in Seattle on February 2. In the playoffs Gagnon played in all 15 games and had three goals and two assists for five points. Gagnon saw action on all four of Seattle?s lines during the season. He stepped up to the top line when Brooks Laich was in Halifax for the World Junior Championships and moved up to the second and third lines at various times during the season due to injuries.
2001-2002: Played for the North Okanagan Midget AA team. In 41 games he scored 59 goals and had 59 assists for 118 points with 60 penalty minutes. He was the team?s leading scorer. Gagnon played two games with the Thunderbirds and was a plus-2 with no points.