Diafra Sakho will undergo a scan on the hamstring injury he sustained in West Ham's 1-1 draw with Manchester United in the Premier League on Sunday.
Sakho scored inside the opening two minutes at Old Trafford, but was withdrawn in the 66th minute after pulling up with the problem.
The Senegal international only returned from a three-month lay-off with a back injury in the 3-2 defeat away at Tottenham on November 19.
Sakho, who has been dogged by injuries since joining West Ham from Metz in 2014, led the line on his own against United and became the first Hammers striker to score this season.
It was also his first strike since May 10, coincidentally against United, in West Ham's 3-2 victory in the final ever match to be played at the Boleyn Ground.
West Ham return to Old Trafford on Wednesday to face United in the EFL Cup quarter-final, live on Sky Sports 1 HD from 7.30pm, with one of Ashley Fletcher, Simone Zaza or Andre Ayew likely to replace Sakho.
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