Michael Ballack has joined Bayer Leverkusen on a two-year contract.
The 33-year-old, who is missing the World Cup through an injury picked up in the FA Cup final victory, was released by Chelsea at the end of last season.
The midfielder is returning to the Bundesliga and his former club, with whom he reached the Champions League final in 2002
"With my transfer to Bayer Leverkusen a circle is complete. I had a beautiful and successful time here, on which I like to look back on a lot," Ballack said on www.bayer04.de.
"That was a factor in my decision."
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