Friedrich joins Leverkusen

The 27-year-old has signed a contract until June 2010 with Leverkusen.

Friedrich said: “It was the hardest decision of my football career.

“I have a lot to thank the club Mainz 05 and the people here for. I am looking forward to the task in Leverkusen, it will be a great challenge.”

The clubs agreed an unspecified fee.