Neymar has lavished praise on James Rodriguez, saying he hopes the Colombian playmaker's stunning World Cup form ends against Brazil on Friday.

Rodriguez enters the quarterfinal at Fortaleza's Castelao Arena as the tournament's top scorer with five goals and an early favorite for the Golden Ball awarded to the World Cup's best player.

At a press conference at Brazil's training base in Teresopolis, about 100km north of Rio de Janeiro, Neymar admitted the 22-year-old Monaco playmaker posed a major threat to his team's chances of advancing to the semifinals.

"I already knew that he was a great player and he has shown that during the World Cup," Neymar said.

"Football has no age. It's obvious that experience helps, but you have to play and put your talent into practice.

"James Rodriguez is a great player despite his young age. We are both 22, but he has been showing what he is capable of. I just hope that his good run comes to an end and that we can advance, with all respect to him."

Brazil coach Luiz Felipe Scolari raised eyebrows during the team's training session on Wednesday by testing the team without a centre-forward, leaving Neymar as a false nine.

The Barcelona forward said he was not fussed about his role.

"I fit into any formation," Neymar said. "We have an excellent coach and as players we have to do what he says. Whether we have a centre forward or not, we have to play well."

Neymar had words of support for Brazil's much-maligned striker Fred, who has scored just one goal from four matches this tournament.

"Fred is a player that needs passes that leave him clear on goal," Neymar said. "He is a goalscorer. We have been trying as hard as we can to help him get into scoring positions."

Neymar, who has scored four goals for the tournament, played down fears about his fitness. A knee injury forced him to miss training on Tuesday, but the attacker moved freely during match simulation on Wednesday and said he had made a "full recovery".

He added that the Selecao needed to lift a gear after scraping to victory over Chile on penalties in the round of 16.

"Colombia and Chile are very similar," Neymar said. "They are both attacking teams and very fast. We have to make an effort to improve on the way we played against Chile."