The east London outfit will be without their main source of goals for the next four weeks
West Ham forward Marko Arnautović will miss the next four weeks after pulling up with a hamstring injury.
The Austria international hobbled off during the Hammers 3-1 win over Cardiff in midweek.
But now manager Manuel Pellegrini has confirmed that after scans, the striker will be out for the next four weeks whilst he undergoes treatment.
It means Arnautović is likely to miss games against the likes of Fulham, Crystal Palace and Southampton.