Aguero has been at his blistering best for most of the season, scoring 31 goals in 40 appearances for City.
Were it not for a seven-game absence with a knee injury in December and January - and then a wait of another six matches to get back on the scoresheet - his return might have been even greater.
In such form the 26-year-old can stand comparison with the best players in the world and that could attract envious glances from other clubs.
But Pellegrini is not worried that a bid might come in from any of them
He insists Aguero, a Â£38million signing from Atletico Madrid in 2011, is happy and any approach would be rejected out of hand.
Asked if he was concerned about interest in Aguero, the Chilean said: "I don't think so because we are not a selling team and I think that Sergio is very happy here, so he doesn't have any intention to go."
What does surprise Pellegrini is that Aguero was not recognised by his peers with a place in the Professional Footballers' Association team of the year.
The explanation for that probably lies in the fact the voting period overlapped with Aguero's lull after injury - a spell in which Tottenham's Harry Kane was capturing the headlines - but Pellegrini thinks it was an error.
He said: "I don't know the way they choose the PFA team for this year so I cannot talk about that, but I always think Kun must be in every best team."
Pellegrini said last week, after Aguero's superb hat-trick in the 6-0 demolition of QPR, that the striker was getting better and better but still had much improvement to make.
Aguero has said he expects even more of himself, attributing his form this season to superior fitness after radically altering his diet and training regime.
But Pellegrini does not deny that Aguero - who still scored 28 goals last season despite a series of muscle injuries - is enjoying his best season to date.
He said: "I think it is important for Kun
It is the season he has scored most goals in his career.
"But it is important for our team to be a scoring team also, not just for Sergio
I am happy because we continue being the team that scores the most goals and for me that is important.
"It is not so important as winning but you can win and be a scoring team."
Aguero's goals have provided some bright spots in a largely frustrating campaign for City, who failed to mount a strong defence of the Barclays Premier League title they won last season.
They will end the season trophyless and, at best, a distant second to Chelsea.
Pellegrini acknowledges signings will be made but insists they will not be rushed and that an overhaul is not necessary.
He said: "I think it is important to try and work as soon as you can but to try to work in the correct way
You can make a lot of mistakes so it is important to finish the season, to analyse what we did, what we need.
"I repeat it is not a disaster, we did not do all bad.
"Next year, we must make some changes but I don't think we are very far from Chelsea or from other teams
In the games we played against Chelsea we didn't see a better team than our team, but they were more consistent during the whole year
That is why they won the title."
City are at least hoping to finish the season strongly and travel to Swansea on Sunday looking for a fifth successive win.
Pellegrini said: "It is never too late to win
For our team always the most important thing is to win titles, but if you cannot win the title it doesn't mean it doesn't matter if you win or lose games."
Source : PA