Two-time World Cup winner Cafu has backed Neymar to star for Brazil at this summer's tournament in Russia.
Neymar's participation in the 2018 World Cup was thrown into doubt when he suffered a foot injury in February, but the Paris Saint-Germain attacker scored in both of Brazil's pre-tournament friendlies.
The 26-year-old has now netted 55 goals for his country, and former right-back Cafu has branded the forward "one of the best players in the world".
"It's really easy to say that a key player for Brazil is Neymar," Cafu told Omnisport. "He's very exposed and he's the best player in the Brazil squad, in Brazil and, for me, he's one of the best players in the world.
"Today, I can say that Neymar and [Philippe] Coutinho are the two biggest weapons for Brazil. But I'd say Neymar is one of the strongest players in world football and will be the key player for Brazil here."
Brazil will open their Group E campaign against Switzerland on Sunday night.