Known as “Kuba”, he transferred from Polish outfit Wisla Kraków to Dortmund in the summer of 2007 and has made 197 Bundesliga appearances (27 goals and 43 assists) and 24 appearances in the European Champions League (three goals and one assist) for Dortmund.
“Kuba is not just a brilliant footballer but he’s a wonderful person as well. It’s important for him to get a lot of match practice ahead of the European Championships in 2016,” Dortmund sporting director Michael Zorc said in a statement on Monday.
“We wish him all the best with his sporting future in Fiorentina and will be following his progress closely. Kuba has been a wonderful servant to us, celebrated great success with our club and will remain a part of our family forever.”
The Poland international won the Bundesliga title with Dortmund in 2011 and 2012, the double in 2012 and played in the final of the Champions League in 2013.