The Brasileiro side have made a £35m offer for the Manchester City captain, who played for them between 2004 and 2006 before moving to the UK for stints at West Ham and both Manchester outfits.
If a deal were to go ahead it would need to be pushed through before the close of the Brazilian transfer window on July 20.
"It is a big deal and a tough deal, because it is one of a very big nature and it might not be simple," Tevez's agent Kia Joorabchian told Sky Sports News.
"We wait to see. First and foremost we have to respect that City have to make a formal answer. If they do accept, then everyone will be running to make it happen.”
The 27-year-old has recently insisted that he needs to leave Eastlands in order to be closer to his family in Argentina, although his £50m valuation and weekly wage of over £200,000 are regarded as hindrances to a transfer.