Born in Aalborg, Andreasen started his career as a youth player with AaB but soon moved on to Randers FC where he would have a better chance of making the 1st team.
[1] Andreasen made his debut for the Randers FC senior squad on 30 March 2008 in a game against AC Horsens.
After the game Randers manager Colin Todd stated that Andreasen had a bright future in front of him, due to his goal scoring ability.
[2] On 29 April 2009 Randers announced that they had decided to loan out Andreasen to TPS Turku in the finish Veikkausliiga until the end of the 2008-09 season.
On 16 July 2009 Andreasen signed a two-year contract with Danish 1st Division side Thisted FC.