Pulis said that his side's chances would be worse without Chamakh on the pitch because the striker is so capable at dropping off the front line to get involved with play.
"Chamakh won't be fit for Saturday," Pulis said in his pre-match press conference. "It is a massive blow because he plays that position so, so well.
"He is a good player, can score goals and he can drop into that number 10 position. It is a miss, but we have to get on with it."
Palace are currently 17th, three points above the relegation zone.