Captain Marc Guehi has told Crystal Palace he will not sign a new contract and will leave next year, says manager Oliver Glasner.
Glasner said Palace want the 25-year-old England defender, whose current deal expires at the end of the season, to stay.
"They offered Marc a new contract, but he said, 'No, I want to make something different', and that's normal," Glasner said.
Palace could sell Guehi in the January transfer window or he could leave on a free transfer next summer.
Glasner said: "It's how we can deal with this situation.