The 25-year-old is set undergo surgery on the problem after missing both of West Ham’s pre-season games in New Zealand over the last week.
Carroll will now head to the USA for treatment on his left ankle, which means he will miss the opening few months of the Premier League.
Carroll suffered a foot injury last season
It’s the latest frustration for the ex-Newcastle United and Liverpool star, who was a long-term absentee during the last campaign with a foot injury.
"West Ham United can confirm that Andy Carroll will have an operation on ligaments in his left ankle in the United States on Friday," said a statement on WHUFC.com.
"The England international will then have a week of recovery before starting an intensive period of rehabilitation, which is expected to take four months.
"The club would like to again make clear that this is a new injury and not in any way associated with the injury he successfully overcame at the end of last season."
Carroll joins England Under-21s forward Ravel Morrison on the sidelines at the Boleyn Ground, after he underwent groin surgery last week.
