Melliti, who plays for Turkish side Gazientepspor, was a member of Tunisia's 2006 FIFA World Cup campaign in Germany.
The 29-year-old, who also played for Esperance, Olympique Beja and Hammam Lif, represented Tunisia in the 2006 African Cup of Nations as well.
Zamalek are in dogged search for a defensive midfielder, following the persistent injury problems of Tamer Abdul-Hamid and Alaa Abdul-Ghani.
Zaki With Youth
On the other hand, striker Amr Zaki played in Zamalek youth team's 2-1 over Tersana in the U-20 league on Tuesday.
Ruud Krol allowed the Egypt forward to get involved in youth team matches in an attempt to help him gain match fitness.
The unsettled Zaki has not played a first team game since the 1-1 draw with Suez Cement in October, as his problems with the club continued to take place.