"Times change, people too. There will always be a link to the club. But it's good that I start a whole new chapter in the summer. I'm really looking forward to it," said Badstuber, who has spent the second half of the season on loan at Bundesliga rival Schalke.
"Of course it's emotional for me, but I didn't want to let it get to me. I want to play football," said Badstuber, who tore cruciate ligaments in 2012 and again in 2013 before other injuries including a fractured ankle.