Manchester City midfielder Samir Nasri is set for a month on the sidelines with a calf injury.
The ex-France international has been a regular in the City XI so far this season, and was expected to line up against former club Arsenal in the Premier League on Sunday.
However, manager Manuel Pellegrini has revealed he will be without Nasri for at least three weeks.
"Samir Nasri has a calf injury so he will not be fit," he said. "I think he will be out for around three weeks to a month.
But there is some more positive news for Pellegrini, who has seen his attacking line in particular depleted by injuries in recent weeks.
"Vincent Kompany is 100 per cent fit," he continued. "We have some doubts about Edin Dzeko.
"[Aguero] is working with the squad every day and he doesn't have any problem. We will see if he will start."
Pellegrini added Wilfried Bony to his squad this week, signing the striker from Swansea City for a reported £28million, but will have to wait until the player's involvement in the Africa Cup of Nations with the Ivory Coast comes to an end before bedding him into his squad.
"Wilfried Bony is similar to [former City striker] Alvaro Negredo," he added. "He is an important striker inside the box."
