Abdennour was born in Sousse, Tunisia, and started his career at Étoile Sportive du Sahel in 2008. During his spell there, he became the favourite player by fans despite being one of the youngest players in the team. In the 2008–09 season he scored five goals for his club, but they missed on the title and finished third.
On 14 January 2010, Abdennour signed a half-year loan deal with SV Werder Bremen which initially saw him stay at the club until the end of the 2009–10 season. Bremen had the contract option to sign him permanently. Abdennour made six appearances for Werder Bremen, but they did not take up the option to sign him and he returned to Étoile.