Ballack, who moved to the London club for an undisclosed fee, said he joined Chelsea because of there recent success.
"Manchester United came in quite early for me but really I saw the possibilities of Chelsea as being much greater," the 29-year-old playmaker told a press conference.
"They are a stronger team and also London has its attractions, particularly as a family man. And in the final analysis it was Chelsea's aims that attracted me."
Ballack joined Bayern after the 2002 World Cup and helped the Bavarians win both the league and the cup three times.
The Bundesliga champions tried to offer Ballack a new contract but he opted to sign for Russian billionaire Roman Abramovich's club instead.
Ballack's decision wasn't tolerated by the Bayern fans who booed their instrumental midfielder during their 3-3 draw with Borussia Dortmund.