Soccer:Manchester City defender Jerome Boateng is to undergo knee surgery and may only be fit for the final two Premier League games of the season.

City manager Roberto Mancini revealed the full extent of Boateng's injury, which was sustained while on international duty with Germany last week.

"He will have surgery in the next two or three days. Maybe he will be fit for the last two games," Mancini said.

There was more positive news regarding Micah Richards. Mancini said he was hoping that the defender, who suffered a hamstring injury last week while with the England Under-21 team, will be fit in time for the FA Cup semi-final clash with rivals Manchester United at Wembley on April 16th.

"We are trying to get him fit for the semi-final. I don't know if it is possible but we hope."

The twin problem, coupled with Kolo Toure's continued absence following his failed drugs test, leaves City struggling for defenders ahead of their Premier League encounter with Sunderland.

At least Pablo Zabaleta has returned after flying back to South America to visit his ill father.

Striker Mario Balotelli is available, although after yet more negative headlines, Mancini could be forgiven for wondering if he actually made the wisest move bringing the fiery Italian to Eastlands from Inter Milan last summer.

Mancini insists he did, although the Blues chief acknowledges there has to be a drastic improvement in the 20-year-old's behaviour.

"I do not regret signing him," said Mancini. "Mario is a fantastic player. He is a 20-year-old, so it is usual his behaviour is not good enough. I understand this situation very well. Playing here could be a fantastic experience for him.

"He has started 15 games and scored 10 goals. But he has to improve his behaviour. Now, everything Mario does is big news. If he goes into a restaurant and speaks to a woman, five will come forward and say they spoke to him. I have spoken to him. What I said will remain private but I hope he can change his behaviour."