Manchester City manager Manuel Pellegrini has admitted that he is "concerned" about Matija Nastasic as he continues to struggle with a knee injury.
The defender has not featured for the former Premier League champions in their last eight fixtures in all competitions.
"He continues with some pain in his knee," BBC Sport quotes Pellegrini as saying. "He has at least a couple more weeks to recover.
"Of course we are concerned because the doctor doesn't know what happened with him. He made all the exams that he needs, but we don't know what happened with him."
Pellegrini also revealed that Sergio Aguero could return to training next week after he suffered the recurrence of a hamstring problem.