The big Frenchman is well travelled and has had spells at Calais, Lens, Barnet, Hayes, Rushden & Diamonds (loan) Gillingham, Torquay United, Oldham Athletic, Darlington, Accrington Stanley and Walsall. With Gillingham in September 2003 he put in an outstanding performance in the FA Cup to help defeat Premiership side Charlton Athletic. After being released by Walsall, Bossu then went on trial with Aberdeen. After impressing then goalkeeping coach Jim Leighton, he was offered a two year contract. With the help of Leighton, "Bert" was without doubt the most improved player at the end of the season.

Bert left the club on the 28th Aug 2009.