Career
Since February 2013, he has been the manager of Arles-Avignon in the Ligue 2. Club
Dumas started his career at Caen and played there for five seasons before moving to AS Monaco. Dumas played in Jean Tigana"s talented Monaco side which famously put Manchester United out of the Champions League in 1998 on away goals after a 1–1 draw at Old Trafford.
He joined Newcastle United in England in July 1999 before moving back to France to join Olympique de Marseille in January 2000.
Managerial
He would later return to Caen where he continued playing until his retirement in 2004, and where he would later manage. In August 2014, Dumas was appointed as manager of Moroccan Botola side MAS Fez, on a one-year contract.