Yamal, who turned 18 earlier this month, has faced intense scrutiny over his personal life after his birthday celebrations drew widespread attention. The forward's rise to prominence at such a young age has made him one of the most talked-about players in Europe, but Mbappe believes the pressure surrounding him has gone too far.
Speaking on Universo Valdano, the France captain said: "It's clear he has a lot of passion for football, and that's something he must never lose. The rest is his personal life. We have to leave him alone. In football, he's a great player, but in life, he's just an 18-year-old kid.
"At that age, everyone makes mistakes, you do things right, and you do things wrong."
Mbappe added that Yamal should be judged on his performances rather than his personal choices. "In the end, he'll learn through his own experiences and understand what's best for him. What matters is what he does on the pitch. What happens off it isn't important unless it's serious.
"He has great talent and will follow his own path. I wish him all the best."
Yamal has been a standout performer for Barcelona this season, becoming a regular starter under Hansi Flick. Despite missing recent training sessions with a minor muscle issue, he is expected to return in time for the upcoming El Clasico against Real Madrid on October 26.
Mbappe and Yamal are set to face each other for the first time this season, with both players in fine form and the clash at the Santiago Bernabeu expected to have a major impact on the La Liga title race.
Barcelona's injury woes have worsened with the news that star striker Robert Lewandowski has suffered a muscle tear in his left thigh and will be out of action for at least six weeks.
England manager Thomas Tuchel has warned Marcus Rashford not to waste his talent, despite the forward's promising form on loan at Barcelona.
Frenkie de Jong has put an end to months of speculation by agreeing to a new contract with Barcelona, set to extend his stay at the club until 2029.
Barcelona midfielder Dani Olmo is a major doubt for this month's Clasico against Real Madrid after sustaining a muscle injury to his left calf.
