RIO DE JANEIRO (Reuters) - Roberto Carlos and his booming free kicks seemed to be a distant memory as far as Brazil were concerned but, on the eve of the World Cup, the former Real Madrid player's name is being mentioned again.

Thirty-seven last Saturday, Roberto Carlos has enjoyed a new lease of life since returning to Brazil to play for Corinthians where he has joined forces with his former Real Madrid and Brazil team mate Ronaldo.

Last week, he scored against arch-rivals Sao Paulo with one of his trademark free kicks, helping Corinthians win 4-3.

Roberto Carlos, capped 131 times, was made one of the scapegoats for Brazil's relatively early exit in 2006 where they lost to France in the quarter-finals and, like Ronaldo and Cafu, he has not been picked since then.

However, a dearth of obvious choices for the left-back position and his return to form have seen the media speculating on a possible recall.

"I think that, of the 16 years I played for the national team, twelve of them were successful," Roberto Carlos told Brazilian media last week. "And, today it's difficult to find a left back.

"Most of the left-footed players prefer to play on the wing or the left side of midfield."

Dunga, who played alongside Roberto Carlos in the 1998 World Cup team, is not prone to tinkering but left-back is one position where he has chopped and changed.

Since he took over following the 2006 World Cup, he has fielded Gilberto, Marcelo, Adriano Correa, Juan Maldonado and Richarlyson without settling on any of them.

Fenerbahce's Andre Santos had a run of eight games in a row last year, appearing to have clinched the place, but the last three friendlies have seen Olympique Lyon winger's Michel Bastos take on the role.

Michel Bastos, who like Roberto Carlos can hit the target from distance, is known in French football as a winger, but he began his career in left back. "If the Brazilian confederation's fax arrives at home, I will somersault with happiness," said Roberto Carlos.

"I don't want to jump the queue. I'm 37 and when I came back to Brazil, I wasn't thinking about the national team.

"But I'm not going to deny that the World Cup is not in my mind. I'm going to keep working hard at Corinthians and put a doubt in Dunga's mind."

(Writing by Brian Homewood, editing by Justin Palmer)