Hayden Mullins' agent has warned Simon Jordan he must sell his Player of the Year, "if the club wishes to get some financial reward for their role in his up bringing."
Andrew Mills has rejected claims that the club were negotiating an extension to the versatile 23-year-old's contract which only has a year to run.
He said: "I have written to the chairman to say that under no circumstances will he be staying after the end of this contract.
"It is no secret that Hayden believes he will not be able to fulfil his true potential at Palace.
"If the club wishes to get some financial reward for their role in his up bringing, then they need to sell him this summer."
At Friday night's Fans Forum, Jordan confirmed that he may have to sell one of his club's best players to prevent him leaving on a free transfer in a year's time.
He said: "I have a difficult choice.
"Do we hang on to a player that we have developed and invested in and let him go for nothing?
"Or do we sell him and get the best return for the club. It's a real conundrum. We've offered to improve his contract but he isn't looking to stay at the club, and he has a right to develop his career."
Birmingham City have twice expressed interest in Mullins, and made a £600,000 bid for him in January which Jordan rejected as "derisory".
Charlton, Aston Villa and Leicester City could now enter the race for his signature at a similar price.