Wales international Craig Bellamy could be sidelined for up to three weeks with the knee injury he picked up in Sunday's 1-0 defeat at West Ham United.
The Manchester City star has already been ruled out of the midweek clash against Aston Villa as has Brazil international Robinho.
City boss Mark Hughes told the club's official website: "It's not an old injury. It needed to be allowed to settle down for 48 hours before we can look at the extent of it.
"It's the patella, he's torn fibres in his knee. The best-case scenario is two to three weeks.
"Since he came to the club he's carried the fight for us. He's going to be a big miss. Against a team like Villa you need as many of your top players available as possible."
There is some good news for City though as Valeri Bojinov is close to a return to first-team action following an injury-ravaged start to life at Eastlands.
Hughes added: "Unfortunately his career hit the buffers because of injuries but we're delighted he's back.
"We can't put too much pressure on him, but if he stays fit he can establish himself as a top Premier League player."