West Ham loanee David Bentley will be out of action for up to six months after undergoing knee surgery, the club have confirmed.
The 27-year-old, who joined the Hammers on a season-long deal from Tottenham Hotspur at the end of August, was forced to go under the knife after picking up an injury during training.
"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," manager Sam Allardyce told West Ham's official website.
Bentley has made five appearances for the club since moving to Upton Park.