Former Borussia Dortmund defender Christoph Metzelder has claimed that Jurgen Klopp "really annoyed" Bayern Munich during his seven years in charge.
The 47-year-old announced on Wednesday that he will be stepping down at the end of the season.
Klopp guided Dortmund to six major honours, including back-to-back Bundesliga titles in 2011 and 2012, and Metzelder believes that he is the club's greatest ever coach.
"Klopp revolutionised the league with his style and he really annoyed Bayern," he told Goal.com.
"Dortmund celebrated real success. As a result they lost important players. Robert Lewandowski was absolutely key. You can't replace him.
"Dortmund's slogan Echte Liebe (Real Love) was summed up by Klopp. There will be some emotional weeks now. I can't imagine what it'll be like when he says goodbye finally. It was the most successful era for the club. Nonetheless, there was life before Klopp and there'll be life after him."
Klopp has been linked with Manchester City and Arsenal.
Steven Toplis
