كتب : Hatem Maher
"The injury will prevent Afortto from playing against Zamalek," Ahli said in a statement on their official website.
"He will be ruled out of action for three weeks after spraining his ankle in training on Wednesday."
The 21-year-old, a diminutive playmaker with promising dribbling skills, rose to prominence during Egypt's U-20 World Cup campaign in October last year on home soil.
He was expected to become a regular member of Ahli's squad under coach Hossam Al-Badri but struggled to do so, with some childish acts in youth games hindering his progress.
He was largely used as a substitute recently after a string of injuries hit the Cairo giants' key players.
Afrotto came on as a second-half substitute to score twice and steer Ahli to a 4-2 league victory over Police Union in February.
He has become the second Ahli player to be ruled out of the Cairo derby against arch-rivals Zamalek after in-form midfielder Ahmed Fathi, who picked up a groin injury.