The 23-year-old injured his back while playing for Germany in August 2013 and has not appeared competitively since, although he did feature in a friendly for the reserves last week.
Ready for Köln
"I’ve been training with the team and I’m feeling fit again," Gündogan told Sky Sports News. "Before the international break the plan was to use the time to train well and to take another step forwards with the couple of friendly games we planned in.
"Once the international players are back with the squad the aim is for me to be fully integrated back into the team and then to be in the matchday squad again. This weekend that means against 1. FC Köln. As long as nothing untoward happens, I assume I’ll be involved."
Gündogan joined Dortmund from 1. FC Nürnberg in July 2011 and has made 57 Bundesliga appearances for the club under Jürgen Klopp, scoring six top-flight goals. Prior to his injury his outstanding form had enabled him to force his way into Joachim Löw’s Germany squad, and he has eight international caps to date.