Redknapp says he was having second thoughts about he post while in charge of Spurs last season.
"I was enjoying my life at Tottenham and I did wonder how I would cope, if it happened, with what is part-time football," he told the Daily Mail. "I do enjoy seeing footballers every day; being on the training ground.
"I had great players to work with. Bale, Modric, Scott Parker. Fantastic lads. I enjoyed going to Old Trafford, I enjoyed going to Liverpool, to the Emirates. All these amazing places. And I thought I would miss that.
"That was something that kept bothering me. Was it something I really wanted to do? I know what the job brings in the end. Nothing but hassle. We all know that. It’s part of the job. If you don’t get slaughtered you’re going to be the luckiest man in the world. Even Bobby Robson got slaughtered. And I knew that. I thought, 'Do I need that?'
"I was driving when I heard on the radio that Roy had got the job. It happened out of the blue. But I didn’t lose any sleep over it that night. I was almost quite relieved in a way — that I hadn’t been given a decision to make. The decision had been taken away from me."