Nedum Onuoha suffered a dislocated shoulder during Manchester City's 2-0 defeat against Chelsea on Saturday.
It's also feared the defender brok his wrist after falling badly in the 58th minute but manager Seven-Goran Eriksson does not know the extent of his injuries yet.
Eriksson said: "I do not know how bad his shoulder is. He is in hospital, having X-rays.
"Nedum also has a problem with his wrist. We are just hoping it is not broken."
It looks as though Onouha is done for the season, given reports that he has dislocated his shoulder at the very least, and may well have suffered further damage to his wrist when he fell on Saturday.