Manchester City striker Carlos Tevez will miss Saturday's FA Cup semi-final against Manchester United at Wembley, manager Roberto Mancini has confirmed.

The Argentina international injured a hamstring in Monday night's defeat to Liverpool at Anfield and is expected to be out until next month.

"Tevez is not available for Saturday," Mancini said.

"I think he will recover in three or four weeks. It is a big problem but we can't take any risks."

It is a major problem for City given Tevez is by far their most prolific striker.

"It is a big problem," said Mancini.

"But we can't take any risks. We have six games left and hopefully we can get Carlos back for the last two or three games."

It means Tevez would be in with a chance of making the final on May 14 if City make it through to face either Stoke or Bolton.

However, Mancini will be forced to rely on either or both of Edin Dzeko and Mario Balotelli to derail United's Treble bid.

"I still have to decide what to do," said Mancini.

"But both players know this is an important chance for them.

"Every player knows this is an important moment for the club.

"If we will we can go to a final, so every player will give 100%."

There is some good news for City though as full-back Micah Richards has returned to training and is expected to be fit after suffering a hamstring injury on England Under-21 duty at the end of last month.

"Micah Richards is available," said Mancini.

"He trained two days ago and again yesterday. He will be okay."