The Sao Paulo club confirmed today that they are in talks with the striker with a deal likely to be struck before the end of the week.

Ronaldo has been out of action since sustaining a knee injury while playing with AC Milan 10 months ago.

The injury had threatened to bring the three-time FIFA World Player of the Year's career to a premature end, with Milan opting not to renew his contract when it ran out in the summer.

Despite that Ronaldo continued his recovery with Flamengo, training with the Rio de Janeiro giants since September, in a bid to make a return to the game.

That now seems certain following Corinthians' interest with Grava revealing the club had sent the 32-year-old to Rio last month to test his fitness.

And while Grava admits Ronaldo is still some way short of his peak condition, he thinks the striker will be able to take his place when Corinthians begin their Campeonato Paulista campaign against Barueri on January 21.

Grava told Radio Bandeirantes: "I think his recovery will allow him to slim down to a good weight in 30 days' time. It will not be the ideal, but acceptable."

Whether Ronaldo takes part in that match is still reliant on him signing a deal with Corinthians, although that seems a formality following a statement from the club today.

"The Board of Sport Club Corinthians Paulista are negotiating the signing of forward Ronaldo Nazario, 'O Fenomeno' (as he is nicknamed)," read a statement on the club's website today.

"All the details are being sorted out by the president Andres Sanchez, the director of football Mario Gobbi Filho and the director of marketing Luis Paulo Rosenberg.

"In the upcoming hours, the parties should finish the negotiation and set a date to unveil the player."

The player's agent, Fabiano Farah, expects the former AC Milan striker to put pen to paper on a Corinthians contract before the weekend.

He told GloboEsporte.com: "There is a verbal agreement. In two days, it will be translated into a contract so Ronaldo can be considered a Corinthians player as soon as possible.

"Corinthians are being led by very serious people and we are very happy about that."

Corinthians, who won promotion to the top division of Brazilian football for 2009 by winning the Serie B tournament, last month played down a move for the ex-Barcelona and Real Madrid frontman with president Sanchez claiming the deal was financially "impossible".

It now looks to be only a matter of time before the move is complete, however.

Gobbi Filho told told Terra.com.br that Ronaldo will sign a one-year contract with the Sao Paulo club.

"The only thing I can say in advance is that he has been hired for one year, with an option of one more," he said.

"The formal event to unveil him may be on Friday. The contract will be signed shortly.

"This is a very big marketing movement. It involves companies. It is not so simple."

Rosenberg told Lancenet.com.br: "This is more a marketing agreement than a player signing. That is why I am taking part in this. It will be a very original and profitable business."