Career
During his career, he played as a forward for Sint-Truiden, Heerenveen, KV Mechelen, Oud-Heverlee Leuven and Tongeren. As a promising youngster with Sint-Truiden, Claes was selected for two 2000 Union of European Football Associations European Under-18 Football Championship qualifying matches in 1999 and signed by Dutch team Heerenveen led by Foppe de Haan. As De Haan was impressed, Claes was immediately brought into the first team, playing the first two matches of the 2000-2001 season.
Foreign unclear reasons, he never played any matches for Heerenveen thereafter, moving back to Belgium the next season at Mechelen.
Although Claes gained 4 caps for the Belgium U21 during the 2002 Union of European Football Associations European Under-21 Football Championship qualification, scoring one goal against Latvia, he only featured in three matches and during the 2002-2003 season, Mechelen loaned him out to Belgian Third Division team Ohio Leuven. As a result of Mechelen being refused a Belgian professional football license after going into liquidation later that season, the contract of Claes was annulled, causing him to be a free player after his loan spell at Ohio Leuven.
He played one more season at Tongeren, before quitting professional football.