Teerasil started his football career playing youth football for Assumption College Thonburi in 2003, aged 15. Two years later he left the club, due to the lack of a professional team (it was only founded in 2011).
In 2005 Teerasil joined Royal Thai Air Force, initially assigned to their youth squad.[1] In the same season he made his senior debuts, and scored three goals in only six matches for the club.
In 2006 Teerasil moved to Raj Pracha, being an important offensive unit for the side, being the club's topscorer (nine goals in 18 games) and also assisting in further five goals during the campaign.
In 2007 Teerasil joined fellow second divisioner Muangthong United, and was a part of the squad who was crowned champions, contributing with seven goals and six assists.