Gundogan flirted with a Premier League move during Jurgen Klopp’s time in charge of Dortmund and finally made his move to England this summer.
Klopp was quoted by ESPN as saying: “Gundogan thought about leaving for a while. It was to be expected.”
The former Dortmund boss was responsible for first putting Gundogan on the map and the Germany international of Turkish origin established himself under the stewardship of Klopp.
Gundogan initially joined the Bundesliga giants from Nuremberg in 2011 and helped the Bundesliga giants reach the 2013 Champions League final working alongside Klopp.
The City midfielder will now face his former boss in the Premier League next season but has been ruled out for the opening weeks of the Premier League with an injury.
The 24-year-old is now one of four players born in Germany of Turkish origin in the Premier League with the others being Liverpool star Emre Can, Arsenal playmaker Mesut Ozil and West Ham winger Gokhan Tore.