Barcelona team-mate Lionel Messi and Real Madrid's Cristiano Ronaldo have set the standard in football, going head-to-head for club and individual honours season after season.
Ronaldo beat Messi to The Best FIFA Men's Player, having regained the Ballon d'Or from his rival, but Cafu believes 24-year-old Neymar will surpass the star duo.
"A little bit of continuity," two-time World champion and Champions League winner Cafu told Omnisport at the Florida Cup when asked what is missing from Neymar's game.
"If he is given this, he'll be the best in the world in a few years. I have no doubt about that."
Neymar has made a slow start to the season for Barca, scoring seven goals in all competitions.
The Brazil forward has four goals in 14 La Liga matches this term but has not scored in the competition since October, although he did net a penalty in the Copa Del Rey win over Athletic Bilbao last week.