West Ham United boss Slaven Bilic has revealed that injury-hit striker Diafra Sakho will be out of action for the next "six to eight weeks" of the campaign.
The Senegal international has only made two appearances for the Hammers this season due to a long-term back problem and hamstring tear, which he suffered against Manchester United in November.
West Ham were hopeful of having the 26-year-old available for the busy Christmas period, but another setback means that the forward will not feature until 2017, also ruling him out of the Africa Cup of Nations in January.
"We have a few knocks but are expecting everyone to be fit except for Diafra Sakho who will be out for six to eight weeks. Sakho had to do a back operation," Bilic told reporters.
"He will miss the Africa Cup of Nations and it is a big blow for us. They're talking about even March for him to be back, so he's definitely ruled out of the Africa Cup of Nations."
West Ham will look to record their third straight Premier League victory when they travel to Swansea City on Boxing Day.