West Ham midfielder Mohamed Diame could be ruled out for up to three months after tearing his hamstring against Liverpool yesterday.
Diame was stretchered off with the Hammers in the lead but two goals in three minutes sunk the home side and resulted in defeat.
The Senegal midfielder has been in fine form for the Irons this season and will be sorely missed especially in the busy festive period.
Manager Sam Allardyce told BBC Sport: "For us he is about the start and build-up of most of the creative side of our game.
"He runs at defenders with pace and ability that puts them on the back foot.
"That is what we have lost and what we will be missing for a number of weeks so we are going to have to be a bit more dogged and resilient."