West Ham winger Victor Moses have been ruled out until the New Year with hamstring injury.
Moses picked up his injury in Saturday's 0-0 draw at Manchester United, and manager Slaven Bilic has ruled him out for four to six weeks.
Also expected to be sidelined till the new year is defender Winston Reid who was injured in training on Wednesday and could be set for a long spell out, with the results of a scan expected on Friday.
Both players injury are the latest additions to a growing casualty list at Upton Park.
The Hammers have already lost summer signing Dimitri Payet and Diafra Sakho until February, while Manuel Lanzini is out for six weeks with a thigh problem suffered in training.
Enner Valencia has been out for five weeks with an ankle injury but he could give Bilic a boost by being added to the squad to face Stoke on Saturday.
Reacting to the news, West Ham coach Slaven Bilic, described Moses injury as a blow to the team.
"Victor is out for four to six weeks. It's a blow, we have had six injuries since the Everton game. Before that we had a full squad, then Payet and Valencia were injured against Everton and now we have four muscle injuries," Bilic told reporters.
"I am hoping Lanzini will be back for the Swansea game. Payet and Valencia are also looking good, we will have to wait and see."
The former Croatian international called on the fit players in his squad to stick together and cover the absences.
"We are now missing six very important players, but we can't complain," he said. "We need to get over it and do well with the players we do have.
"We have a very good medical team here so hopefully some players will come back quicker than first expected. Of course it will be difficult without players like Lanzini, Payet and Sakho, but we played without all of them at Manchester United.
"Now it is about the squad and the character of the players we have, it is time for them to step up and help the team."