Slavisa Jokanovic is adamant two of his young stars are going nowhere in January even though both can walk for free in the summer.
The Whites head coach insists winning games is more important than up to £8 million in the bank.
If so, they can expect a battle with Jokanovic.
"I can make money or not for the club," he said. "My part of the business is to be successful on the pitch.
"To be successful we need to stop any moves.
"Fans dont want the club to have 10m, 20m or whatever they want their team to win games.
"To try to do this I need the staff to do this and the business must understand this."
Neither Hyndman nor Dembele have shown any inclination to sign new deals with Fulham, but the club would be entitled to compensation payments should both 19-year-olds decide to leave at the end of the season.