Career
Matthiasson began his career in 1992, playing in Division 1 with Almtuna, based in his hometown of Uppsala. He spent four seasons with them until moving to another Division 1 side Timrå. In 1997, he moved up to the Elitserien by joining Djurgården.
After a disappointing season he moved back to Division 1 with Huddinge and in 1999 he returned to Timrå, guiding them to promotion from the Allsvenskan to the Elitserien.
He stayed until 2004 when he joined the Malmö Redhawks where they were relegated to HockeyAllsvenkan. 2006-2007 was a huge disappointment to Matthiasson as he followed his stellar performance in the last season with just 8 goals in 55 games as Malmö were relegated again.
In 2007, Matthiasson joined Slovenian side Acroni Jesenice, who play in Austria. He was second in points with 32 behind fellow Swede Conny Strömberg.