Carroll to miss start of season
The 25-year-old has been ravaged by injuries since his move from Liverpool was made permanent at the start of last season.
Carroll made 24 Premier League appearances on loan at Upton Park during 2012-13, but during the previous campaign he was troubled by a foot injury and played just 15 times in the league.
On Thursday, the England international took to his Twitter account to break the news.
"Going under the knife tomorrow morning and absolutely devastated to be missing the start of the season," the tweet read, along with an image baring the words "I'm busy getting stronger" attached.
Jack Sullivan, son of West Ham co-chairman David Sullivan, had earlier posted about the matter, claiming Carroll could be out until at least Novemeber due to the issue.
"Very bad new[s] regarding AC, torn ligaments in ankle...operation tomorrow with top surgeon in USA...will be playing in four months," he said.