Raphael Varane believes Kylian Mbappe is an "alien" who could win the Ballon d'Or.
Paris Saint-Germain youngster Mbappe, 19, scored four goals at the World Cup, including one in the final as France beat Croatia 4-2 to lift the trophy for a second time.
Mbappe also won the award for best young player in Russia and Varane told L'Equipe: "If he does not win the next Ballon d'Or, we will tell him that it is not normal -- we will yell at him! Yes, Kylian is a more precocious talent than I was. His intelligence and maturity really left an impression -- his talent is monstrous.
"I have known some extra-terrestrial talents in my time, but I think that this is the first time that I have met a young alien! Everything moves quickly. When I speak tactics with him prematch, I do not have time to finish my sentences -- he has already understood and assimilated it.
"Whatever happens, I advise Kylian to keep playing the same role for Les Bleus -- he will certainly become even more important over the years. He should continue to do what he knows how to do, without trying to burden himself by doing too much, and stay this way -- he should remain focused on his role for the team.
"You cannot demand of somebody just 20 years old to fill the role of a 35-year-old veteran. When you burst onto the scene early like Kylian has, expectations are high."
Midfielder Blaise Matuidi has also praised Mbappe, pointing at his performance in the 4-3 win over Argentina in the World Cup round of 16 as the moment the teenager announced himself to the world.
"We knew that we had a phenomenon among us," the Juventus man told Le Parisien. "To do what he did against Argentina in the round of 16, though, that is something else ... I tipped my hat to him that day.
"Europe already knew it, but the entire planet was made aware of Kylian on that day -- he is on track to become a Ballon d'Or winner in the next few years."
Matuidi is confident Mbappe will remain grounded but admitted that Didier Deschamps' players did have to bring him back down to earth when he first joined the squad.
"He has very good people around him, with a football-focused brother, as well as a mother and father who are there," said Matuidi. "However, when he joined the squad for the first time, we could not just tell him that everything was beautiful and great -- we had to play our part. That involved telling him certain things, particularly early on."
Mbappe himself has spoken of his "indescribable pride and the "unique feeling -- a childhood dream come true" after winning the World Cup.
"Having made the French people happy is priceless," he told TF1. "My life is changing every six months, or year, and it will change again. However, it will not change my way of life too much.
"People thought I was crazy, perhaps arrogant [when he said France should target winning the World Cup pre-tournament]. It was just pure ambition, though. When I see what I have achieved, I tell myself that it was a good thing that our ambitions were so high."
"I want to relive this unique sensation. In Qatar, come 2022, or the Euro before that in 2020 -- the goal is to win, win, win."