The player, who signed a four-and-a-half-year deal at Selhurst Park in January after a successful loan spell, is likely to have attracted interest with a number of impressive performances in recent weeks, says the London Evening Standard.
But Pulis says he is not for sale and insists he will not be leaving.
The Palace manager said today: "If Jason is playing well and there is an offer, you have to accept that is going to happen. You have to get on with it because that is the market. Gareth Bale played exceptionally well for Tottenham and they sold him to Real Madrid, it happens at every football club. But Jason is doing really well for us and we would not want to sell him.
"He has played well over a period. But he has to keep his feet on the ground. When he is at 100 per cent, he is a good player. If he drops off, then he drops below the standard we need for our team to function."
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