That is the view of manager Fabian Hurzeler, who will be without several key players.
Lewis Dunk is absent, while Adam Webster is also out, which leaves only Jan Paul van Hecke and Igor as fit senior central defenders.
Hurzeler told reporters: “Of course, we have some issues in the centre-back position, but Lewis will be back very soon.
“I think also Adam will be back sooner (than expected), then we have four central defenders.
“They are all able to play, they have already proved they can manage games in the Premier League, so I don’t think that it is necessary to do any signing in the center-back position.”
Hurzeler added: “Lewis has a small muscle issue, not that big. He’s a great healer.
“We have to go day by day and for sure we can’t take any risks with him.
“But he’s keen on coming back as soon as possible.
“So we have to go day for day and then we will see when he will be back.”