The transfer ban handed down to Barca makes it difficult for them to loan the defender back to his Brazilian side for a year, but he is expected to sign for the Spanish side.
The right back has long been linked with a move to the Catalan giants, with Sao Paulo confirming Wednesday that a move is imminent.
The Brazilian club wishes to see the 24-year-old loaned back to it for a season, but with the combination of the transfer ban handed down to the Spanish side by FIFA and the Brazilian transfer window being closed, things have become difficult.
The player must be registered at Barcelona before being loaned back to Sao Paulo, with the alternative being that Douglas wouldn't be able to make the move to Camp Nou until 2016.
Despite the confusion and disruption, vice-president Gil Guerreiro insists that the player will join Luis Enrique's side.
"We have everything resolved with Douglas, but no contracts have been signed yet," Gil Guerreiro told Radio Globo. "There is a small problem now that we're trying to solve. We asked Barcelona to loan Douglas back to us for one year.
"But with their FIFA sanction, they can't. Now our lawyers are studying the situation to see what can be done. But the deal is done, Douglas will be a Barcelona player."