Due to the conditions of Moses' loan, the winger is ineligible to play against his parent club, meaning that Bilic will be without one of his in-form players.
The Croatian boss has suggested that Enner Valencie could come into the Hammers' line-up to replace Moses, with Winston Reid also out.
"Compared to the Palace game we are without Victor Moses of course, it’s a big blow for us but we knew that when we signed him," he said. "Winston Reid isn’t going to make it, the injury isn’t major but he won’t play. All others are back available, Enner Valencia could start."
Moses has been a crucial part of the Hammers' line-up so far this season, so Valencia will have big boots to fill if he is included in their team to face Chelsea.
The Ecuadorian forward is yet to figure in the Premier League so far this season, having been ruled out through injury for much of the campaign, but he will be eager to prove his worth to Bilic if given a chance.
He will step into a West Ham side full of confidence, too, after their highly impressive start to the 2015/16 campaign.
The London club have climbed into fourth place in the Premier League table, and a win over Chelsea would strengthen their claims to securing a European spot this season.