كتب : Amro Hassan
Hamza's contract with Zamalek is set to expire next month, and the international forward reached an agreement with Mainz officials to play for the club next season.
"Everything has been settled with Mainz. Now we are just awaiting Zamalek to send them Hamza's international card," Zekri said.
The 28-year-old will be the second Egyptian to sign for Mainz after Mohamed Zidan played for the club over two spells between 2005 and 2007.
Mainz recently won promotion to the German Bundesliga after spending last season in the first division.
Hamza, who played 16 times and scored four goals for Egypt, won three Egyptian Premier League titles, two Egypt Cups and one African Champions League.