Aaron Wan-Bissaka is said to be close to competing a move to Manchester United.
Crystal Palace are looking for at least $63.5 million to complete a transfer for the 21-year-old right back.
Aidy Boothroyd, England's U-21 manager, said that Wan-Bissaka's potential move is distracting his on-field play.
"I think when you are nearly going to move and all the things that would go through an older person’s head, who is more experienced in life, it would be difficult for them to cope with. For a young player who all he knows is Crystal Palace academy, Crystal Palace first team, it would be daft not to say that in some way he must think about it," said Boothroyd.