Chamakh will miss the trip to Sunderland and could be out for a few weeks.
Pulis said: "It is a pretty bad one, which is a blow for us because he has done so well. He has been a real quality player for us. He has enjoyed the position we have asked him to play and he has got some quality. We have played through him and played some really good football when he has played.
"He will be a big miss as he has been very good since I have come to Palace. He has got that little bit of quality you need and he has played exceptionally well since I have been here. So it is a big blow in lots of respects."