Silva has missed City's last five games in all competitions due to a calf injury.
And giving an update on the Spain international on Friday at a press conference to preview Saturday's Barclays Premier League trip to Southampton, Pellegrini said: "Maybe on Monday, he will be ready.
"We'll see the way he works tomorrow and on Sunday, and I will then decide next week (about whether he might be involved against Bayern)."
Pellegrini's side have already qualified for the Champions League knockout stage ahead of the Bayern contest, their final Group D game.
The Saturday after that match, City have a Premier League home fixture against current table-toppers Arsenal, who they trail at the moment by six points.
Meanwhile, Pellegrini is optimistic that City skipper Vincent Kompany will be fine to keep his place in the team for the Southampton match.
The Belgium defender, who has been sidelined by a thigh problem, made his first appearance since October 5 on Wednesday, playing for the whole of the 3-2 league win at West Brom.
Regarding Kompany, Pellegrini said on Friday: "Vincent is okay. We will see if he can play two matches in less than three days. But he is okay.
"It is not an easy decision. But I think he finished the last game without any problem.
"We will wait a few hours more to see that he has made the perfect recovery and I will decide. But I don't think it is a great risk for him to play another game."
Along with Silva, City will be without defender Matija Nastasic and striker Stevan Jovetic - who have both also been nursing calf complaints - for the Southampton game.