Career
Jonson began his professional career in 2005 with Swedish club IFK Sollentuna appearing in 24 matches and scoring 3 goals. In 2006 he was transferred to Vasalund/Essinge IF which then played in Division 1. Prior to joining Vasalund he had a trial spell with Benfica.
With his new club he quickly established himself as a starter, initially playing primarily at right back, and later converting to center back.
In 2009 he appeared in 29 matches, playing a full 90 in all appearances. With Vasalund/Essinge IF and Vasalunds IF he appeared in 86 league matches, scoring 2 goals.
During the 2010 off-season Jonson went on trial with New York Red Bulls but the club did not sign him.