The 27-year-old joined West Ham from Tottenham on a season-long loan deal on transfer deadline day and made five appearances for the Hammers.
“It is a great shame for David as he had settled in well to the squad,” Hammers boss Sam Allardyce told the official club website.
Tottenham said: “David Bentley has undergone surgery to his left knee…[and]…is likely to be out for up to six months.”
