Jadon Sancho has been warned that "there are limits" over what Borussia Dortmund deem to be acceptable conduct amid growing links with a move to the Premier League.
The England youngster has been in superb form for the Bundesliga side this season, clocking up a stunning 14 goals and 15 assists across 26 appearances in all competitions.
Such form has prompted suggestions that the former Manchester City youngster could be set for a return home to England, with Liverpool, Chelsea and Manchester United all linked with moves.
But there have been concerns about Sancho's discipline, with the teenager fined back in October following a late return from England duty, and also dropped for a Champions League clash at Barcelona after missing a team meeting.
Dortmund officials are delighted with the progress he has made this season on the pitch, but are said to be monitoring his behaviour off it.
"I have rarely seen a player who has developed in such a short time," said the former Dortmund player turned players licence department director Sebastian Kehl to t-online.de, via Goal.com.
“Like every other player, he has to know that no matter how good you are, there are limits. There is a certain framework in which all players can move with us.
"Football is a team sport. You have to be consistent and make a tough decision in the interests of the group.”
Sancho could soon be joined at Dortmund by the former Liverpool midfielder Emre Can.
The German international midfielder is set to tie up a move back to the Bundesliga on transfer deadline day, joining Dortmund on loan from Juventus with a view to a permanent transfer at the end of the season.
