Career
He is a utility player at home in the front row, second row or centres, Martins brings a great deal of versatility to the Catalans squad
Sebastien has signed to play for National League 1 team Leigh Centurions until the end of the 2007 season. He was signed from French League team Pia XIII. He has been named in the France training squad for the 2008 Rugby League World Cup. Martins continued to represent France in the 2009 Four Nations tournament.
In April 2014 Sebastien joined North Wales Crusaders as cover for the departing Ryan MacDonald.