Borussia Dortmund midfielder Emre Can has warned Jadon Sancho that he must keep his behaviour in check if he hopes to join the world's elite.
Sancho, 20, is rated as one of the game's finest young footballers thanks to his exploits for Dortmund in recent seasons.
A sensational hat-trick in the club's 6-1 thrashing of Paderborn underlined his potential, with Manchester United among the clubs interested in the former Manchester City trainee.
The same week as those heroics, however, Sancho found himself in hot water alongside a host of BVB colleagues for breaking coronavirus social distancing protocols in order to get his hair cut .
The DFL handed down a fine for that breach, a judgement that the player declared an "absolute joke."
But Can, who popped up to score his side's only goal in a 1-0 victory over Hertha Berlin on Saturday, advised his young colleague to watch his future conduct.
"We know that he just has to be more disciplined in some things, but he knows that himself," the ex-Liverpool and Bayern Munich man told Sky .
"He just has to be smarter and grow up with things like that. He can't afford to make such mistakes in the future.
"You have to lead Jadon the right way. He's a great boy, even off the pitch. He doesn't do it on purpose to cause a scandal.
"Maybe he trusts too many other people in some things."
Germany legend Lothar Matthaus also called on Dortmund's senior squad members to lead the way, telling Sky: "If the club or the DFL cannot regulate [social distancing measures], then the players simply have to regulate it. There are such experienced players at Borussia Dortmund.
"They have to take Sancho aside and say to him: 'Listen, it doesn't work! You hurt not only yourself, but you harm us, the club. Such things don't belong in public right now!'"
BVB sports director Michael Zorc added to Sky when asked about the case: "I can only warn against permanently attaching it to a single player. Others have had their hair cut too.
"With Sancho, it is simply the case that he is not only noticeable on but also outside the pitch. Sometimes this is not easy for us.
"We try to do that and work with him and his management on it. Giving up is not an option for us."