Mancienne is the only English player in the Bundesliga, and left Chelsea in 2011 after six years at Stamford Bridge. He made just four league appearances in that time, and enjoyed extended loan periods at both QPR and Wolves.
The defender has made 21 appearances this season, a total that would have been greater but for an ankle ligament injury suffered in January.
Mancienne, who has three years remaining on his Hamburg deal, insists that the decision to leave Chelsea was not a difficult one.
"It was going to be a new challenge, a different phase of my life and an exciting opportunity," Mancienne told the Guardian.
"I knew the time was right, a chance to create my own name and not be the youngster trying to come off the bench at Chelsea. I wanted to be playing regularly and obviously I knew that would be a pretty much impossible task at Chelsea.
"It was hard but it just made me more hungry to play football because I knew that I couldn't sit on the bench and rot away.
"To be honest, I don't really think about Chelsea now. I'm happy where I am and feel blessed to be at such a big club."