All-time club record goal scorer Aguero has been out of action for the best part of a month with a thigh problem.
However, the Argentine striker made a welcome return to training on Monday.
Silva meanwhile sustained a leg injury during the derby defeat to Manchester United earlier this month.
Both are expected to be side-lined for Wednesday’s Carabao Cup quarter-final trip to Oxford United.
Quizzed about Silva, Guardiola revealed the Spanish midfielder could also return to training later this week.
“David is not ready for tomorrow (Oxford) but we will see after that,” said the City boss.
“Thursday or Friday he could train for Leicester and then we will see.”
“Yeah, Sergio is coming back and is part of the session. It’s not like Leroy (Sane) of course, it’s different, but it’s the next step to be part of the training session with the team.”
Sane, meanwhile, has been out of action since the start of the season after damaging the anterior cruciate ligament in his right knee during the early stages of our Community Shield win over Liverpool at Wembley.
But after four months out, he returned to the training pitches at the CFA on Monday to step up his recovery, completing a pitch session in isolation.
However, though a huge boost to see the German winger stepping up his recovery, the City manager cautioned that it was still far too early to talk about a projected date for his return to action.