Redknapp told the Sun: “Joe Kinnear is not visiting Newcastle to collect a nice little nest egg — don’t be shocked if he is still there in 18 months.
“If Joe manages to turn things around and get a few results, the fans will love him.
“If owner Mike Ashley cannot find a buyer for the club for a while and things settle down on the pitch, Joe could well be left to get on with the job for a few months.
“And one thing Joe is good at is motivating players. It was the main weapon in the armoury for the old Wimbledon Crazy Gang under Joe. And look what they achieved.
“Self-belief is the key. Newcastle have a great deal of quality players on the books, unlike the old Dons.
“Joe will have to convince the players to stop feeling sorry for themselves, tell them the owner’s problems are not their problems and it is no excuse.
“Sometimes a new face around the corridors can do that.”