The 28-year-old suffered major cruciate ligament damage in Dortmund's 1-1 draw with Hoffenheim in April. He underwent surgery and was sidelined for around seven months later.
Last summer while he was still on rehab, he traveled to Egypt but failed to get back to Germany in July as planned because he couldn't issue a travel clearance from the Egyptian military administration.
A travel clearance usually does not take much time to be issued but Zidan had problems related to his compulsory military service.
It took the Egypt ace around a couple of months to settle things down with the army.
After making his Dortmund comeback in the 3-0 victory over Ukraine's Karpaty Lviv, Zidan revealed the bright side of his injury.
"I couldn't just leave the country as I'm a role model for many at home and I didn't want my name associated with this," he told his club's official site.
"But due to the cruciate ligament injury I was rejected as unfit for service. So the injury was good for something after all."
Fantastic
In Thursday's Europa League match, Zidan started on the bench before being introduced seven minutes past the hour mark instead of Japanese attacking midfielder Shinji Kagawa.
The former Hamburg man went close to scoring with a low drive in the second half but Lviv keeper blocked his effort. He was also involved in Dortmund's third goal.
Zidan also played in Egypt's 3-0 victory over Australia in a friendly game last month. He scored the last goal upon converting a penalty kick.
"It was a great feeling when the fans welcomed me back. Just fantastic," said Zidan. "Both comebacks ended with the same result and both times I was involved in the third goal."
Old Steam Engine
Dortmund manager Jurgen Klopp believes that Zidan is still facing a fitness battle.
"These 25 minutes have taken him a little further," Klopp commented on Zidan's Dortmund return.
"He may have looked like an old steam engine. Playing games and training are two different things.
"Zidan's making progress step by step."