2002-03: Led the USHL in playoff goals as he captained Lincoln to the league championship. Missed significant time during the regular season due to a broken wrist. Was taken 78th overall in the draft by the Wild, who dealt their 3rd and 4th round picks in the draft to move up and take him.
2003-04: Irmen’s freshman season with the Minnesota Golden Gophers (NCAA). It took a little while before Irmen settled in, but once he did, he started producing more consistently and seeing more power play time. He finished the season with 22 points on 14 goals and 8 assists in 44 games and really came on strong come playoff time, scoring clutch goals in the WCHA and NCAA tournaments.
2004-05: Irmen’s NCAA breakout season for a Gopher team with low expectations going into the season that went all the way to the Frozen Four. Co-led the Gophers in goals with 24 and was second on the team in points with 43 in 43 games. Named to Third Team All-WCHA and co-winner of his team’s John Mariucci MVP award and winner of his team’s Mikke Crupi Most Determined Player award.
2005-06: Described as the heartbeat of his Gophers team, this season was marred by injury and Irmen was limited to 30 games. Still, he managed 38 points on 16 goals and 22 assists, enough to be named to his second Third Team All-WCHA and his second Mike Crupi team award. Also named National College Player of the Month for January 2006. At the conclusion of the season, Irmen signed with the Wild and played four regular season and seven playoff games with the Houston Aeros (AHL).
2006-07: In his first full season with Houston, Irmen had 37 points on 17 goals and 20 assists. Three of his goals were shorthanded, second best on the Aeros.
2007-08: While Irmen played effectively, his role changed. He was mostly taken off of the special teams, and skated mostly in a checking role. As a result, his numbers suffered, dropping to 23 points on 10 goals and 13 assists.