As a player, Tobiasen played as a right-back or centre-back for a number of clubs in Denmark, the Netherlands, and Norway.

In February 1996, Tobiasen moved on to the Dutch Eredivisie club SC Heerenveen, as he hoped to emulate the success of fellow Dane Jon Dahl Tomasson.

[7] Tobiasen had initially agreed a free transfer move effective from his contract expiry in summer 1996.

[13] After one-and-a-half years and 34 matches for Heerenveen, fellow Eredivisie team Ajax Amsterdam spotted his talent.

[14] Having immediately established himself in the starting line-up, Tobiasen suffered a knee injury in November 1997,[15] and did not return to fitness until July 1998.

[22] In the summer 2005 transfer window, Tobiasen was loaned out to AaB for six months, where he played regularly in the central defender position through the first half of the 2005–06 Danish Superliga season.

In February 2007, Tobiasen returned to the Netherlands and joined MVV Maastricht in the second-tier Eerste Divisie league.

Instead, Tobiasen agreed to become youth team coach at Roda JC[26] and played in the 2010–11 season at Hoofdklasse side EHC Hoensbroek before retiring from the game.

[7] He featured in the Danish qualification campaigns for the 1998 FIFA World Cup and Euro 2000, but due to injury he missed out on both final tournaments.

Tobiasen earned a total six caps for his country, before his persisting injury problems saw him dropped from the team.