But his agent, Alessandro Beltrami, believes he will be with the London club at the start of next season.
He said: "Valon is thinking about the World Cup, his future will be discussed later.
"West Ham have declared him non-transferable, so I think it is 99 per cent certain he will remain in England.
"Talk of Palermo? That is good because it means the player has done well.
"However, we are happy that West Ham have made him unavailable for transfer."