The Egyptian international has been out of action since suffering a serious cruciate ligament injury in a league game against Hoffenheim last April.

"The 28-year-old Egyptian is currently continuing his treatment in the United States," Dortmund said on their official website.

"If everything goes perfectly, he can start doing the football exercises in the second half of October.

"Before the end of November, Zidan will be back again wearing the black and yellow jersey."

Zidan was not sorely missed though as Dortmund made their best ever Bundesliga start.

Jurgen Klopp's side, who lie second in the table, bagged 18 points from their first seven games.

They are just three points adrift of leaders and surprise package Mainz, who secured maximum 21 points.

Zidan was a regular member of Dortmund's starting line-up last season but he could now face a stern challenge to regain that place.

The likes of Paraguayan Lucas Barrios, Japanese Shinji Kagawa and 22-year-old forward Kevin Grosskreutz formed a powerful frontline in Zidan's absence, scoring 11 goals between them.

Zidan missed Egypt's 1-1 draw at home to Sierra Leone in their opening game of the 2012 African Cup of Nations qualifiers.

He will also not be available when the Pharaohs face Niger away from home on Sunday.