WEGGIS, Switzerland, May 25 (Reuters) - Brazil coach Carlos Alberto Parreira rejected on Thursday suggestions that his fullbacks Cafu and Roberto Carlos are too old for the World Cup.

Cafu, who is heading for his fourth successive World Cup, and Roberto Carlos, who is due to play his third, have a combined age of 69 and many Brazilians are worried that they could leave the defence vulnerable.

"It depends on how you can look at it," Parreira told reporters after a training sesson on Thursday.

"You can see them as old or experienced and, as far as I'm concerned, they are experienced, which is fundamental if you're trying to win a World Cup.

Parreira has already announced that, barring injuriess, both players will start the team's opening match against Croatia on June 13.

He said that the pair were in the team on merit.

"They don't have automatic places in the team, they're not season ticket holders," he said. "They're here because they've been playing well and, physically, they're in good shape."

Cafu has played only a handful of games for AC Milan this year and has just recovered from a minor knee operation, while Roberto Carlos's performances for Real Madrid have received widespread criticism.

"You have to respect the fact that Cafu is playing his fourth successive World Cup, so he will begin as captain," said Parreria. "They give confidence to the other players."