 On September 10, 2011, Benhadj Djillali made his debut for CS Constantine as a 73rd-minute substitute in the opening round of the 2011–12 Algerian Ligue Professionnelle 1 against JSM Béjaïa.A week later, he scored his first goal for the club in a 3-1 loss to ASO Chlef.On January 3, 2012, Benhadj Djillali was loaned out to Saudi Arabian club Najran SC until the end of the season.