Mark Hughes is facing the prospect of being without key central defender Robert Huth until the New Year.
Huth has been told he needs surgery on a knee problem which has been causing him pain for several weeks and forced him out of action early in last weekend's 2-0 victory over Sunderland.
Hughes has been informed by the club's medical staff that the knee requires a minor operation as well as a clean up of the joint and he can expect to have the defender missing for around a month.
The manager had been expecting Huth to miss Saturday's trip to Everton, but the need for surgery for a player who has been ever present this season and so influential since he moved to the club is a big blow as the Christmas and New Year period looms.
"Unfortunately, Robert has got a problem with his knee. We hoped we would be able to manage him through it, which we have tried to do," Hughes explained. "But the situation has become more difficult for him and it looks like he will have to have an operation and that will rule him out for a number of weeks."
Huth's absence leaves Geoff Cameron, Marc Wilson and Marc Muniesa competing for the vacancy alongside skipper Ryan Shawcross for the difficult trip to Everton and the prospect of trying to keep Romelu Lukaku quiet.
"We've got good players that can come in to give us decent options. These are players who have played centre half on a number of occasions, not just for Stoke, but for their national team as well," Hughes said. "Last weekend's win for us was vital. If we can get another win that would take us up into the top 10 and that is where we want to be as a club."
Hughes will also have to do without the services of Marko Arnautovic, while the forward continues to recover from a hamstring problem, but Stephen Ireland is available again after injury as is Kenwyne Jones.
The Trinidad & Tobago striker was unavailable for the Sunderland victory because he returned from international duty with a shoulder complaint, but Hughes said: "He's got a little bit of an issue with his shoulder, but he trained yesterday [Thursday] and should be available. He's got it well strapped up."