Carroll suffers fresh injury setback
The striker, who moved to Upton Park in the close-season on a permanent basis from Liverpool after a successful loan spell in 2012-13, has not featured for Sam Allardyce's side since the last day of the previous campaign due to a heel injury.
Carroll was pencilled in to make his return to first-team action in this Sunday's Premier League fixture at Southampton.
However, the England international now looks set for another period on the sidelines after hurting his right foot during his first full training session after recovering from his heel complaint.
"Although it is in the same part of his foot as his previous injury, it is a new injury and therefore there will be no prognosis until he has seen a specialist," a West Ham statement read.
The 24-year-old made 24 Premier League appearances for West Ham last season, scoring seven goals.