West Ham defender Winston Reid is out for the rest of the season while Sam Byram is likely to stay sidelined until the summer also.
The All Whites skipper needed oxygen as he was stretchered off the field in the first half of Sunday's 4-1 defeat to Swansea City, his first game in nearly two months.
Reid was taken to hospital after twisting his knee during the Hammers' 4-1 defeat to Swansea on Saturday.
David Moyes' side have been dealt a blow in their push for Premier League survival with Reid and Byram suffering from knee and ankle issues respectively.
But rather than the massive rise being down to an increase in money generated at their significantly bigger new home, which is still unpopular with many fans, the Hammers' coffers were instead swelled mainly by TV revenue and player sales.
Arthur Masuaku's six-game ban for spitting will end after the Burnley clash.