Hart was dropped for long-term back-up Costel Pantilimon last month after a series of mistakes and has sat out City's last six Barclays Premier League games.
Pantilimon has done little wrong in his place but, after Hart featured in Tuesday's final Champions League group fixture at Bayern Munich, there has been speculation the Englishman could face Arsenal on Saturday.
City host the Premier League leaders in a much-anticipated clash at the Etihad Stadium and there is a theory that Hart's greater big-game experience could earn him the nod.
But if that is true, Pellegrini gave little away when he met media to preview the match and chose instead to state his faith in both goalkeepers.
He said: "I repeat, on Saturday we will see. I trust a lot in Joe, he's a very good goalkeeper.
"We'll see when is the best moment to bring him back. Costel deserves respect. He is doing very well and the team are winning almost all the games.
"We have two goalkeepers and we'll see when is the best moment he can return."
Pellegrini's decision to axe Hart, 26, has also sparked plenty of rumours that the club could move to sign a new keeper in the January transfer window.
Such has been the frequency of goalkeeping questions at recent Pellegrini press conferences that the Chilean laughed off the latest stories.
He said: "Now when the transfer window starts you will have a lot of difficulties to know who the first-choice goalkeeper will be because we will have Casillas, Valdes, Neuer, Caballero, Begovic - so I think you will have to ask me about six new goalkeepers."
One player almost certain to return against the Gunners after sitting out the win in Germany is captain Vincent Kompany.
The Belgium defender was rested after recently making his comeback following a 10-game absence with a thigh injury.
Pellegrini said: "He didn't play in midweek so he is perfect for this game.
"I think it was a risk to use him just 72 hours later in the week that he has returned.
"We will see in the future - maybe he won't have any problems to play two games in a row but this week it was better for him to rest."
Arsenal have a six-point advantage over City but Pellegrini's men boast a 100 per cent home record and have a perceived advantage this weekend because their midweek Champions League game came a day before the Gunners'.
Pellegrini said: "I think that every manager wants the best for their teams, but we have to play the 26th and 28th - maybe Arsenal will play 26th and 29th.
"Every week there is something which gives one team an advantage, but it's not important."
The discrepancy between the home form and away form - City have won just two from eight on the road in the Premier League - remains a source of mystery but European travels show what the team are capable of.
Pellegrini said: "We are working to try to play similarly (away) to how we do at home.
"That's why it was so important the game we won in Munich. It meant we have won the three Champions League games away.
"You'll see in the Premier League what will happen in the future, but we will continue to work and play in our style."