Cesar has been strongly linked with a move back to Serie A to play under Rafael Benitez in Naples but negotiations are ongoing.
"Something more will be known tonight," said De Laurentiis on Thursday, speaking from Napoli's summer camp in Dimaro.
The Brazilian goalkeeper is among Napoli's chief targets as they look to reinvest the cash from the sale of Edinson Cavani.
A loan deal had reportedly been suggested but QPR boss Harry Redknapp was quick to rule out such an arrangement.
"It's absolutely pointless," he told Sky Sports. "What's the point loaning a player and then he comes back to you the following year on massive wages.
"He's in his prime at the moment and wanted by many clubs around the world so now is the time really. We need to move on.
"If he wants to leave then he goes and we sell him. Napoli are not short of money. They've just sold a player for £54million so if they want him then they've got to do a deal."
"Let's do a deal that suits the football club rather than just doing deals that suit agents and other people."