Paris Saint-Germain coach Thomas Tuchel has said World Cup winner Kylian Mbappe can improve significantly on certain aspects of his game.
The France international, 19, has won Ligue 1 twice with two different clubs and was also named the best young player at the World Cup in Russia as Les Bleus won the trophy for a second time.
Speaking at a prematch news conference on Saturday ahead of Sunday's Classique against bitter rivals Marseille, Tuchel called on Mbappe to step up.
"Kylian is just 19," Tuchel said. "Despite his exceptional qualities, he can improve in all areas -- he can still progress with his defending, as well as his ability to find spaces and exploit them.
"Players like Kylian like to play and want to show their qualities. They like matches and they cannot wait. Kylian needs light to show his talent off."
Meanwhile, Mbappe's strike partner Edinson Cavani has gone three appearances without scoring a goal and Tuchel admitted the Uruguay international is not in the best of spirits.
"Edinson is over-thinking things," he said. "He is not satisfied as he has not scored for a few games now and also a little tired after travelling a lot with Uruguay.
"Against Amiens and Napoli, 'Edi' did everything. However, he wants that goal a little too much. Sometimes, patience is necessary.
"I told him that it will happen, he just needs to keep working for the team."
Tuchel also said he remains unhappy with the lack of an additional defensive midfielder, with Adrien Rabiot and Marco Verratti his only two natural options in the role.
"Yes, finding a new No. 6 was and still is a priority," Tuchel said. "It is dangerous to always utilise Adrien and Marco -- we must get a third top level player.
"I remain convinced that Marquinhos can play there, but we cannot dream about what we do not have -- we are trying to improvise."
If PSG win at Marseille on Sunday, they will equal Tottenham Hotspur's top five European league record of 11 consecutive victories at the start of a season.