Gianfranco Zola has resigned as Birmingham City manager following Monday's home defeat by fellow Championship strugglers Burton Albion.
Former Italy global Zola resigned after a 2-0 home defeat to Burton Albion that left Birmingham three points off the relegation zone.
Zola faced the press soon after the announcement and he said: "I am sorry because obviously I came here with huge expectations, from the club and myself".
To say the decision to replace Gary Rowett with Gianfranco Zola in December 2016 was unpopular, is an understatement, and with hindsight it is something that Birmingham's owners may regret.
The club are 20th in the Championship table, three points above the relegation zone, and Redknapp told a news conference: "It was something I thought I'll have a go at".
Redknapp has also managed two other London clubs in West Ham, for whom he played, and Tottenham.
'Birmingham is a proper football club but they are in a precarious position.
His first game in as City boss is on Sunday lunchtime against bitter rivals Aston Villa in a Midlands derby at Villa Park.
"I've gone in there, said I will come and do it".
He said: "I have watched every game Derby have played probably over the a year ago and a half".
Zola had controversially replaced Gary Rowett and Birmingham City's subsequent downturn in form sees them now in 20th place, just three points above the relegation zone.
"I love football, I am football mad". He is one of the top coaches I have worked with. "If I can get them going and get a bit of belief back in and pick up a win or whatever we need to stay up, that's all I can do".
But the change of manager baffled many supporters - and results on the pitch have done nothing to win them over.
"I was anxious how I was going to find a centre half among the jockeys with them all being so small".