Ballack upbeat about Chelsea comeback
"I am making excellent progress," Ballack told Germany's state television channels ARD and ZDF.
"I started training again last week and December is looking like a good time (for a return)."
The Germany captain is due to train tomorrow as he works towards his comeback, although he is not going to predict exactly when he expects to return.
He said: "I am just going to see how it goes from week to week, but won't set a date for when I would like to play again."