When asked how much fight he has still left in him, the former Germany and Bayern Munich star said: "A lot. I am 32 years old.
"I am ready, but of course I need more training sessions to have the right rhythm, to be where I want to see myself.
"My head is more than 100 per cent. I feel quite comfortable. The session was pretty intense today [Wednesday] and I could do it, so that was good.
"I was preparing before I came here and, of course, I need some more days on the training pitch but I feel I am ready whenever the coach needs me."