David Silva could be out of action for as long as a month after picking up a calf strain.
The Spaniard played 66 minutes of City's 5-2 Champions League win at home to CSKA Moscow on Tuesday night but is now facing a spell on the sidelines.
Manuel Pellegrini: "I don't know how many weeks at the moment, but it could be three or four.
"It (the Kompany injury) was diagnosed as being a five-week problem.
"That was three weeks ago, so he should be fine in another two weeks.
"We hope if he continues this way he will be fine."
Source: Manchester City MAD