And Redknapp says he advised Rams owner Mel Morris to appoint a young manager at the start of last summer.
"A year ago, when Derby had lost their manager and I rang Mel Morris (Derby's owner) and asked him who he was going to give the job to and he said an experienced manager. And I said 'Mel, you keep picking managers and you are not doing very well at the moment," Redknapp said.
"I said 'take Frank Lampard' and he said 'no, I want experience', so I said 'take Frank Lampard! He will be a different class for you, he will bring so much to your football club - he is a special talent.'
"In the end he listened and two months later, he is ringing me and saying 'Harry, I am so glad I listened to you he is amazing.'"