West Ham have confirmed that David Bentley is set to be sidelined for up to six months after undergoing knee surgery.
Skysports.com revealed earlier on Wednesday that the on-loan winger was facing up to a lengthy spell on the treatment table.
Bentley, who moved to Upton Park on a season-long loan from Tottenham over the summer, has undergone an operation on his left knee.
The procedure could keep the England international out of action until April.
The news comes as a major blow to Bentley as he had been hoping to resurrect his career at Upton Park.
West Ham are also disappointed to lose a player of proven Premier League pedigree after seeing him make just five appearances for the club.
Hammers boss Sam Allardyce told his club's official website: "It is a great shame for David as he had settled in well to the squad.
"We wish him well and hope he has a speedy recovery."
While Bentley is facing up to a lengthy spell on the sidelines, West Ham are hoping Winston Reid, Mark Noble and Matt Taylor will be back in contention for their home date with Blackpool on Saturday.
The club have also revealed that goalkeeper Robert Green is making positive progress in his recovery from a knee operation carried out on 30th September.