Gundogan was managed by Klopp at Borussia Dortmund, before eventually going to City.
And the German is full of praise for both.
"They are the two best coaches in the world. It is a privilege that I trained under both," Gundogan told Fantasy PL.
"I think there are a lot of footballers who are jealous of me are because they didn't have that opportunity.
"Both have a place in my heart. Both have taught me a lot and are part of my success."