The two sides meet at the Etihad Stadium this afternoon and Redknapp was quick to point out the pressure is on the hosts.
"City are not throwing money around for fun," Redknapp told the Sunday Mirror
"The sheikh and the club's supporters expect Mancini to deliver and if they don't win the Premier League title who is to say they won't sack him and bring in someone who can?
"Personally, I quite like Mancini and I certainly don't blame him for spending the money he has. I would if I was in his position. But you have to accept that with it comes pressure and rising expectations."
The statement is the latest in a war of words between the two managers ahead of today's clash.