Five players will miss City’s game against Bournemouth through injury.
The City boss confirmed the extent of the lay-offs in his pre-match press conference at the Etihad Stadium.
“Sergio has a muscle injury – it’s an important injury so I don’t think he will be back before one month,” Pellegrini said.
“Silva has a kick in his ankle – he’s also out. Delph and Clichy continue to recover with old injuries. Kolarov also has a hamstring injury.
“We’ll see how they [Aleks and David] improve in the next week – I hope both of them can be back in 15 days.
“Delph maybe one week more he will be working with the squad.”
Pellegrini also seemed to hint that Vincent Kompany will not make an immediate return to the starting line-up after representing Belgium in midweek.
The Chilean admitted he would have preferred it if his captain had not played and revealed that the club sent a medical report to Belgium Head Coach Marc Wilmots explaining why.
However, Pellegrini accepted that the laws dictate Wilmots had the right to play the defender.
“I was not pleased because we sent Vincent with a medical report saying he cannot play but as the Belgium manager said, he can do what he wants,” Pellegrini declared.
“If a player withdraws from a national team squad, he cannot play for his club team in the next game. Vincent didn’t play in our last three games - it’s not my duty to do it but some day clubs will protest that as it should be the same thing the other way.
“It’s no problem with Vincent. It was just important for him to work a whole week before playing a game – he couldn’t do it because he played with Belgium so we’ll have to see when he can return to his position for us.
“The national squad have all the rights to do what they want, we can just make a suggestion with a medical report. They decided after a week he can play – maybe it’s better to make a call but they didn’t and he played.”
Aguero’s injury puts the spotlight on Wilfried Bony who looks the most likely to replace last season’s Golden Boot winner.
Pellegrini handed his backing to the Ivorian but pointed out that it’s the responsibility of the whole team to score goals.
“I always trust Wilfried – he’s a very good player,” Manuel emphasised.
“He’s had very bad luck here. He arrived here in January, he went to the African Cup and then he had problems with his knee.
“Last season he couldn’t demonstrate what he can do but now he has the responsibility.
“It's not just Wilfried, we also have Kelechi – the team is the most important thing, how we are moving forward.”
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