Man City boss Eriksson confirms Onuoha out for season
Manager Sven-Goran Eriksson told the club's website: "He is out for the rest of the season, but hopefully he will be okay when we start pre-season.
"The doctor has told me he will be out for three months.
"He had surgery today, but I'm told that at this stage it looks good although he is going to be out for a long time now."
Onuoha joins fellow defender Micah Richards - who recently had a knee operation - on the sidelines.