The Paris Saint-Germain forward, who has equalled Zinedine Zidane's France goal-scoring record, has already netted three goals at the tournament and will likely be hunting the tournament's golden boot.
Les Bleus have already secured their place in the knockout stage of the World Cup, following wins over Australia and Denmark, which means Deschamps is expected to rest many starters to protect them from injury and fatigue against Tunisia.
Mbappe is unlikely to be dropped as he is chasing further records, but Deschamps has claimed that there is no pressure from the player to keep starting him, as he is a team player.
"Physically he's very good. So the problem is his ego? What do you know? Does he want to play? Kylian doesn't have an ego," said Deschamps, as quoted by L'Equipe.
"Ultimately, he is important, and pivotal, and takes the spotlight with his performances, but he is always part of the collective.
"He is no longer 18, he has experience. The 24 (players) want to play. They won't all start.
"You can think and imagine but I have live data that you don't have."