Negredo has benefited from Pellegrini's tough love previously, when the manager sold him from Real Madrid to Sevilla in 2009.
Pellegrini's arrival in the Spanish capital coincided with Negredo's return from Almeria, with Real taking advantage of a buy-back clause after his impressive form.
Negredo was not in Pellegrini's first-team plans though, and the Chilean quickly advised him to move on - something he did to great effect with Sevilla.
That straight-talking was appreciated by Negredo, who was persuaded to join free-scoring City by Pellegrini in July.
"Madrid had exercised the option to buy me back from Almeria (in 2009)," said Negredo, who has already scored 23 goals for City this season.
"But it coincided with all these players arriving, so suddenly I had Cristiano Ronaldo, Karim Benzema, Gonzalo Higuain, Raul, Ruud van Nistelrooy and Klaas-Jan Huntelaar in front of me.
"But I was thankful to Manuel right from the word go because he didn't keep anything from me. He didn't make me go through the entire pre-season in the hope that I might be featuring that season.
"He told me straight and just said, 'Look, you're not going to be in my plans.'
"He doesn't hide from talking to you face-to-face, and that's what a dressing room wants from a manager. They want to know clear ideas and be spoken to plainly."
Negredo's goals – 14 of which have come in cup competitions – have kept City's ambitious aims for a quadruple alive.
They currently sit second in the Premier League, will play Sunderland in the League Cup final and have reached the FA Cup's last 16.
There is also the small matter of a UEFA Champions League round-of-16 tie against Barcelona for Pellegrini's men to deal with.
Negredo feels the quadruple is possible and has suggested he and his team-mates have yet to reach their peak.
"The quadruple is possible simply because we're still involved in all four competitions," he added.
"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 (110 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."
