And, as a sweetener, the Blues were allowed to have Glen Johnson on loan for the 2006-07 season.
Grant initially arrived at Fratton Park in June 2006, under the banner of technical director.
The appointment was driven by Chelsea owner Abramovich, a close personal friend of the former Israel national boss.
Abramovich had approached purported Pompey owner Sacha Gaydamak over finding Grant a role at Fratton Park.
Yet while Gaydamak was willing – a reticent Redknapp almost quit over it.
The former Blues manager told The News: ‘After keeping Pompey in the Premier League, I went to Israel for a meeting with Sacha Gaydamak over dinner, it was my first visit to the country.
‘He said: “Mr Redknapp, what do you think about bringing in a coach who understands tactics in football”.
‘I replied “What do you think me, Joe Jordan and Tony Adams do?”, to which he responded “Yes, but this man is very clever. He understands the diamond formation”.
‘I said: “The diamond formation, very good. I saw an under-10s team playing like that over the park on Sunday and it was very good. It’s a good formation”.
‘When I asked who this man was, I was told Avram Grant. Well, Gaydamak was informed that I didn’t want him, I didn’t need anybody else.
‘So I’ve come out of this meeting, I’ve only just got to Israel and I’m ready to go home. And I’m ready to quit Pompey.
‘Then a very close friend of mine called – and I explained what was going on.
‘He told me: “Harry, if he’s going to bring in Grant, why would you walk out? You’ve done a miracle and kept Pompey up, you shouldn’t leave over this”.
‘The next day I had another meeting with Gaydamak, who said: “Listen, if we take Avram Grant, we can take one, maybe two players on loan from Chelsea. Would you like Glen Johnson?”.
‘Of course I would.
‘The owner continued: “Mr Abramovich will let us have Glen Johnson if you give Avram Grant a job”. Now how does that work? The owner of Chelsea is telling Pompey who to employ, incredible isn’t it.
‘I replied: “So why doesn’t Mr Abramovich give Avram a job?”, to which Gaydamak responded “He wants him to come to England to work at Portsmouth”.
‘So give Avram a job and we get a player like Glen Johnson on a loan for nothing, Chelsea probably paid all his wages. Yes, I’ve changed my mind!
‘Gaydamak added: “Even if he sits on the PlayStation all day, you can do what you want with Avram”.
‘The owner was something to do with Abramovich, business or whatever, and just wanted to please him.’
Grant would spend a season at Fratton Park in the role, during which the Blues claimed ninth in the Premier League, missing out on Uefa Cup qualification by a point.
The following summer, in July 2007, Grant was appointed director of football at Chelsea and, within three months, took over as manager following Jose Mourinho’s departure.
That season he steered them to the 2008 Carling Cup final, where they lost to Spurs, while finished second in the Premier League.
Chelsea also reached the 2008 Champions League final, losing on penalties to Manchester United, with Grant sacked three days later.
He returned to Fratton Park in October 2009 as director of football, with Paul Hart now manager, and the following month became manager, overseeing relegation and the 2010 FA Cup final.
Redknapp added: ‘I loved Avram, I got to like him as a person, I thought he was a good guy.
‘I enjoyed having him there, he was no threat to me, he was there as support. We would chat away, he wasn’t taking training sessions or anything.’