Making his competitive debut for Belgium in the qualification phase for EuroBasket 2009, Dreesen progressed through the country's junior programmes. He featured at cadet level in 2003, playing in the U16 European Championship a year later, at U18 level in 2006 and then at the U20 European Championship in 2007 and 2008. Dressen began his professional career in German's third tier with Hertener Löwen, quickly moving to Phoenix Hagen and playing a vital role in their promotion campaign to the second tier. He failed to establish himself in the following BBL season and moved back to his native country to play for Gent but was sent on loan to Division 2 side Zolder. He joined Luxembourg side Sparta in 2011, helping them to become the champions of the Diekirch League, before returning to the Ethias League with Aalst last season, where he also competed in the EuroChallenge.