Fulham boss Felix Magath says they're powerless from preventing Patrick Roberts leaving.
Arsenal and Liverpool were linked with the 17-year-old but interest cooled over the summer as both sides concentrated on big-name targets such as Mario Balotelli and Alexis Sanchez.
"I am not involved in contracts or changing players here and there - I have nothing to do with that," Magath said when asked to put a valuation on Roberts.
In Demand: Both Arsenal and Liverpool have shown interest "In football things change very fast. Sometimes you ask for a player and they say £3million - then they score two or three more goals and they ask for £10m. You cannot say he is worth this or that.
"We want to develop young players and it depends how good they are and how good we are. If the young players have a future we can give them the level they are ready to play at - then I hope they will stay here. But if we are not at that level and the player is extraordinarily good and there is interest from Champions League clubs then you will never be able to hold them, especially if the player doesn't want to stay."
