A regular Davis Cup player for Morocco during his career, El Aarej made his debut in 1996, for a World Group qualifier against Switzerland in Olten.

[3] He also had a win that year in the Davis Cup over Switzerland's Michel Kratochvil, who was at the time ranked in the world's top 40.

[6] His best performance on the ATP Tour came when he made the doubles semi-finals at the 2004 Grand Prix Hassan II in Casablanca, with Mehdi Tahiri.

Fourth in the singles, he lost his semi-final to top seed Nicolás Almagro in a final set tiebreak and was beaten in the bronze medal playoff by Simone Bolelli.

[8] El Aarej, who had a Davis Cup win over Filippo Volandri in Rome in 2005, continued representing Morocco until 2008.