Erik Rasmussen got his career underway while playing high school and university hockey in his home state of Minnesota. After winning the Minnesota High School Player of the Year honours in 1996, Rasmussen was a member of the All-WCHA Rookie Team, and later that summer was drafted by the Buffalo Sabres upon completion of his first year at the University of Minnesota in 1996. He stuck around for one additional campaign with the Golden Gophers and then made the jump to the pro ranks, splitting his first two seasons between the Sabres and the AHL's Rochester Americans.
A silver medallist with the U.S. World Junior team in 1996, towards the end of his second campaign at Minnesota, Rasmussen got the nod to join Buffalo in advance of their playoff run to the finals in 1998-99. While vying with the Leafs for the Eastern Conference Championship, Rasmussen scored the series-winning goal to put the Blue and White out of the race. The Sabres went on to lose out to the Dallas Stars in a hard-fought Stanley Cup final.
Rasmussen went to play five seasons with the Sabres before he was traded to the Los Angeles Kings in the summer of 2002. In his only season with the Kings, Rasmussen was limited to 57 games before being acquired by the New Jersey Devils in the summer of 2003.
Aside from his World Junior experience in 1996, Rasumussen returned the following year and then went on to make his World Championship debut in 2002.