Oestre director of football Mauro Guerra has admitted that the Brazilian outfit are powerless to stop Antonio Carlos leaving the club in November.
Carlos is currently contracted to Corinthians, but he agreed a loan deal with the second-tier side at the beginning of the season.
Oestre had hoped to keep the 19-year-old on a long-term basis, but it is understood that Manchester United are preparing a move for the defender.
"The player is under contract with us until the end of the second division season. But he is still a Corinthians player, so Corinthians have all the power in negotiations," Guerra told Globo Esporte.
"When their board decide to have the player back he will have to return, be it to play for Corinthians or to negotiate with another club."
A host of European clubs are reported to be monitoring the proceedings.