Brazil are looking to lift their sixth title at the 2022 World Cup in Qatar and their first since 2002. Rafael, a teammate of Neymar's at the 2012 Olympics, says the Paris Saint-Germain forward is "not a leader" but believes he can be the best player in the world if he rids himself of off-field distractions.
"We need Neymar, that's for sure," Rafael told ESPN. "We need him a lot. He needs to improve a lot of things outside the pitch. It's important for a footballer. He needs to improve a lot outside the pitch to come inside the pitch and do his best. I hope he can do that and if he does we have a big chance to win.
"Neymar is not a leader. I don't think he's a leader. It's not him. He can do the things he does because if he is good, if he's focused and concentrated, he is the best player in the world."
Neymar, still the most expensive footballer in the world following his move from Barcelona to PSG in 2017, has often made headlines for his antics.
Laurens: Not on board with Rafael's comments on Neymar
Julien Laurens says Rafael's comments about Neymar's leadership come from an outsider's perspective.
The timing of a birthday party in February at a Paris nightclub for Neymar also became a point of discussion since the Brazilian star had recently suffered a rib injury.
Rafael, now with Lyon, has watched the 28-year-old up close in Ligue 1 and says he needs some tough love to get the best out of him.
"Football has to the first option of your life," said Rafael. "He has so many things around him. He thinks in his mind 'I don't need to do that' to play well but you need to.
"There are a lot of things you need to do. If he does that and someone can put this in his mind -- I know him and I've played with him -- I know he's hard guy to listen to orders. It's not good with him.
"I say the truth but sometimes people don't want to listen to the truth. They want you to say 'you are good, you are magic' they want you to say all the good stuff but life is not like that.
"I think he needs to listen more and if he does that it will be hard to stop Brazil."