フォルトゥナ・シッタート
Dekker played his last match on 10 March 1985, and became a football manager, who coached Fortuna Sittard, FC Eindhoven, United Arab Emirates outfit Al-Jazira, FC Den Bosch, Qatar U-17, RBC, Sparta Rotterdam and Fortuna Sittard once again. He also was Academy boss at Feyenoord.