Striker Michail Antonio is a doubt for West Ham's Europa Conference League match against Anderlecht on Thursday.
The Hammers are top of Group B and will advance as group winners if they beat the Belgian side and Danish team Silkeborg fail to beat FCSB of Romania.
West Ham won 1-0 in Belgium last week, thanks to Gianluca Scamacca's goal.
"Micky Antonio has had a wee bit of cold, or the flu, which has kept him out of training a day or two," said Hammers boss David Moyes.
"We're a little bit unsure on him. We've got a couple of knocks and niggles but hopefully, he will be OK.
"We've won five out of six at the moment and I've sensed the belief coming back in training.
"I'm seeing an awful lot of things and thinking 'this is looking good and going in the right direction'. I hope I'm right in what I'm observing."