Theo Zwanziger has admitted that he had serious doubts about the former Tottenham striker's ability as a coach during the 2006 World Cup, and was planning to replace him
The 67-year-old has written a book about his time in charge of the organisation, and claimed that a contingency plan to install Matthias Sammer as coach was drawn up.
"I have to admit that I was beginning to have doubts about our team coach. Publicly, I expressed loyalty to Klinsmann, but internally, we set up a plan B," an excerpt from the book, published in Bild, read.
"If there would have been looming a disaster in 2006 and we couldn't have hold on Klinsmann, we decided that Sammer should replace him on short notice.
"If it would have come that far, we would have told him early enough. Fortunately, we were not forced to do this."
Germany reached the semi-finals of the 2006 World Cup, and current boss Joachim Low replaced Klinsmann shortly after the tournament.