City boss Roberto Mancini had initially expected Richards to be out of action for only one week after the right-back was injured during Britain's Olympic quarter-final defeat against South Korea.
But the problem is worse than first feared and, speaking after City's 3-2 win over Chelsea in the Community Shield at Villa Park, Mancini confirmed he will be without the England defender for at least the first month of his side's Premier League title defence.
City kick off their league campaign against Southampton next weekend and Mancini, said: "With Micah, we thought it was a small injury but instead he will longer.
"He has a problem with his ankle, a big problem maybe, and it may be one month out."
There was another blow for Mancini as City goalkeeper Joe Hart missed the Community Shield with a back injury which will keep him out of England's friendly against Italy in Berne on Wednesday.
But Mancini doesn't believe Hart will be sidelined for long.
"Joe had a problem yesterday (Saturday) with his back but I don't think it is serious," Mancini said.
Source: AFP
Source: AFP