كتب : Hatem Maher
"Al-Nahhas will head back to Germany after a month to continue his treatment," Ahli said in a statement on their website.
The 32-year-old defender suffered cruciate ligament damage in Ahli's 1-1 Egyptian League draw with Ismaili last month.
Ahli skipper Shadi Mohamed has struggled to fill the void left by Al-Nahhas injury.
The Red Devils conceded four goals in three matches since Al-Nahhas was injured.