West Ham United are waiting on the results of a scan on Diafra Sakho's latest injury after the striker was injured during the 1-1 Premier League draw at Manchester United on Sunday.
It was only the Senegal international's second appearance of the campaign following a long spell out injured, but he could now face another four weeks on the sidelines with a hamstring problem.
With Andy Carroll and Andre Ayew having missed the majority of the campaign and summer signings Simone Zaza, Jonathan Calleri and Ashley Fletcher all misfiring in front of goal, manager Slaven Bilic has another headache ahead of Wednesday's return to Old Trafford in the EFL Cup.