Neymar believes Kylian Mbappe is a "phenomenon" but backed his Paris Saint-Germain team-mate to keep improving.
Mbappe hit 13 Ligue 1 goals in his first PSG season but has proven far more prolific in 2018-19, scoring 26 times to help the champions dominate the league again.
Edinson Cavani and Nicolas Pepe have scored 17 goals each with Mbappe a virtual certainty to win Ligue 1's top-scorer award for the first time.
Mbappe is also proving himself at international level and has broken Karim Benzema's record as the youngest player to reach 30 appearances for France.
The striker has also scored 12 times for Les Bleus, including four goals in their triumph at the 2018 World Cup under Didier Deschamps.
But Neymar, whose foot injury has allowed Mbappe to take the PSG spotlight in recent weeks, feels there is even more to come from the 20-year-old.
"For me, right now, he is already a phenomenon," Neymar said to DAZN and Goal.
"He can have a great career and become even better than he already is. I have no doubt about it that he will become one of the biggest names in world football.
"He is a calm person, happy, full of joy, always ready to joke around. Obviously, he's still a 'kid' and has to gain more experience."
Pele has suggested Mbappe could be his heir, although Neymar has staked his claim for the title by closing in on the three-time World Cup winner's goals record for Brazil.
"I can't really decide who the second or first best player is after Pele," Neymar added. "For me, we are all important. In the past I've said that every one of us has made history, every one played in a different way and every one has been important at a certain moment.
"There are names that will forever remain etched in history, there will always be important Brazilians in football. Ronaldo, Romario, Ronaldinho, Kaka, Zico, Rivaldo - I could go on forever.
"There are many players who were important in their own unique way, that's why it's so difficult to just pick one. Roberto Carlos, for example, wasn't an attacker but is still a player with an incredible story. So to me, it doesn't make a lot of sense to rank the best players in the 'post-Pele era'.
"I have a lot of respect for the players who made history in the past, all the players that have been called up to the Brazil national team, because they are an example to me, they are my idols. Every single one of them is important."