West Ham defender Winston Reid will miss the rest of the season with the knee injury he picked up in the 4-1 defeat to Swansea last weekend, Sky Sports News understands.
Reid was taken to hospital after twisting his knee in the 27th minute and received oxygen on the pitch after also being knocked unconscious.
Hammers right-back Sam Byram is also likely to miss the remainder of the campaign after sustaining an ankle injury at the Liberty Stadium.
Byram, who replaced Reid, picked up the injury during the first half, but was able to complete the match.
West Ham are hopeful James Collins will return from a slight hamstring injury for the home match against Burnley on Saturday, while Angelo Ogbonna is expected to play after missing the loss at Swansea because of illness.
Arthur Masuaku also serves the final match of his six-game ban and will be available for the home match against Southampton on March 31.