The 30-year-old is making a fight to regain match fitness after enduring an injury-plagued four years at Manchester United, and recently made a shock transfer to Eastlands during the end of the summer transfer window.
According to reports in the Sun, the midfielder is now raring to face Bayern Munich, as the two clubs have been drawn in the same group in the Champions League.
He said: "Bayern is a wonderful club - I had a great time there and won the Champions League.
"I like to measure myself against the best and I've always taken on challenges.
"They are going to be tough opposition and it will be an exciting game."
Hargreaves is aware that he faces an battle to get into the City squad.
He said: "It's important that you get back into a rhythm of playing football and I haven't done that for a while."
The two clubs will face off on 27 September in Munich for their Group A clash.