Ronald de Boer has accused Memphis Depay of spending too much time focusing on off-field antics during his spell with Manchester United.
The Netherlands international saw his time at Old Trafford come to an abrupt end in January when he was offloaded to Lyon, a year-and-a-half after joining the Red Devils on a long-term deal.
Depay had a reputation for caring more about his life away from the pitch than on it and failed to live up to his hype on the field, scoring just two goals in 33 Premier League appearances.
De Boer has offered some stern words of encouragement to the 23-year-old, telling Sport360: "Memphis is a great talent. It just did not work out. He has his characteristics and perhaps he can be smarter at times.
"When people expect you to do things and you don't deliver, don't do other things to attract attention. [Pierre-Emerick] Aubameyang, I saw him in a blue suit, an ugly one in which he looked like a clown, but it is accepted because he is scoring goals, so everyone laughs about it.
"But if you are not scoring goals and playing bad, people will say he is thinking more about his clothes or whatever. They have to be smart, you really have to work."
Depay has found the net three times in seven league appearances since making the move to French football.