Mancini has been widely criticised for his actions on the touchline over the last few weeks.
On Monday night, he appeared to suggest Martin Atkinson should send off Wigan defender Maynor Figueroa for a deliberate handball and two weeks previously the Italian was criticised for waving another imaginary card after Liverpool's Martin Skrtel conceded a penalty in their Premier League encounter at the Etihad Stadium.
Redknapp joined a long list of people criticising the 47-year-old on Thursday ahead of his team's crunch clash with the league leaders on Sunday.
Redknapp told a news conference: "I don't like it. I wouldn't do it. I don't like to see it.
"I don't think there is any need for it. He has done a great job there and when I have met him I have found him a really good guy.
"We all do things we shouldn't do at different times. We get caught up in the game but it's not something I like to see."
Redknapp's men head to Lancashire five points adrift of the big-spending leaders after failing to claim a share of top spot last weekend by drawing 1-1 with Wolves.
Tottenham were on the receiving end of a 5-1 hiding from City in their second game on the season but have only lost once in their following 19 matches - something which leaves their manager confident of a shock victory on Sunday that would blow the title race wide open.
"They are not invincible," Redknapp said.
"I think we can win. We will go there as a positive team. I wouldn't want to go there and sit back. We have people who can hurt them.
"We have good players here and they will be looking forward to it.
"I don't think about losing (the game). I think about going there on Sunday and trying to win."
Redknapp says there is only an outside chance of captain Ledley King being available for the first time since December 22 as he continues to struggle in his recovery from a hamstring problem.
"The last time I saw him on the training pitch was four weeks ago, but it's not impossible (that he could play)," Redknapp added.