Zamalek's international striker Khaled Kamar has been ruled out from the squad to face Moroccan side FUS on Sunday due to a foot injury.
According to the club's official website, the player needs around one week of treatment to recover from his injury.
Kamar, who joined Zamalek from Ittihad El-Shorta last summer, sustained his injury during Zamalek's 2-0 win over Harras El-Hodoud in the Egyptian League on Monday.
Following to their first-leg goal-less draw at home, the White Knights will have a tough mission on Sunday when they meet their Moroccan opponent away.
They will be looking for a positive result to remain in the continental competition.
Zamalek are seeking their first continental title since 2002, when they won the Champions League.
(For more sports news and updates, follow Ahram Online Sports on Twitter at @AO_Sports and on Facebook at AhramOnlineSports.)