Nathaniel Clyne's transfer fee will be decided by a tribunal, it has been announced.
Southampton announced last week that that had completed the signing of the England Under-21s player on a four-year deal.
Clyne's contract had been allowed to run down at Selhurst Park, meaning that the Eagles may not get their £4m asking price for the 21-year-old.
Palace's joint owner Steve Browett said that he is not happy about the situation.
"Southampton are taking the mick," said Browett. "He's going to be a very good Premier League player."
Clyne made 123 appearances for Palace.