Pellegrini arrived at Real Madrid from Villarreal in June 2009, around the same time that striker Negredo returned to the club from Almeria.
Real had exercised a buy-back clause after the burly frontman had enjoyed a prolific two-year spell at the Mediterraneo Stadium.
However, with five full internationals ahead of Negredo in the Bernabeu pecking order, Pellegrini quickly advised him to move on once more - so he headed for Sevilla instead.
And when the opportunity came to team up with the Chilean coach again at Manchester City, the 28-year-old says he did not hesitate.
"He didn't make me go through the entire pre-season (at Real) in the hope that I might be featuring," Negredo told the Daily Mail.
"He doesn't hide from talking to you face to face and that's what a dressing room wants from a manager. He's one of the reasons I'm here at City. It was never tough for me meeting up again."
Negredo joined City on a deal until summer 2017 for an initial fee of around £16.4million, and has already made a major impact at the Etihad Stadium.
He has netted nine goals in 21 Premier League appearances, another nine in just six domestic cup outings and five more in the Champions League.
Nicknamed 'the Beast', Negredo's bustling style makes him a force to be reckoned with but he believes his skill is sometimes underestimated.
"A lot of people maybe make the mistake of thinking I'm just a big strapping centre forward who is going to be barging into defenders and creating trouble physically," added the Spaniard.
"Yes, there is that side to me, but I think I have an extra plus where I do try to show that little bit of invention. I try to surprise people with a touch or something spectacular in a finish."
Ahead of Wednesday night's trip to Tottenham, prolific City are second in the table, a point behind Arsenal. They are also through to the Capital One Cup final against Sunderland; have an FA Cup fifth-round tie with Chelsea to look forward to; and meet Barcelona in the Champions League round of 16.
"The quadruple is possible simply because we're still involved in all four competitions," said Negredo.
"To be totally honest, it would be tough to imagine both myself and the team would be scoring quite as many goals as we have (107 so far).
"But I think there is more to come. As an individual and a team, we're not going to settle for what we've achieved so far."