Hammers boss is Glen Roeder is also likely to be without midfielder Michael Carrick as he to struggles to overcome a groin injury sustained playing for the England under-21 team.
"John Green tells me that Gary Breen has picked up a slight hamstring that might take him out of this week's squad, but he will be fine the week after," Roeder told the clubs official website.
"Michael has got to be a concern, a doubt anyway, because it was only last Friday that he came off at half time in the U21s," added the Hammers boss.
"That is the worrying thing when you let your players go away, you have no say in it and they can pick up an injury.
"We are hoping it is not a serious injury and that he can make Saturday, but we will have to make a late decision as to whether Michael can make it or not.