The European champions have approached Internacional over the 20-year-old midfielder and are reportedly preparing a ?25million bid.
Internacional president Giovanni Luigi insists the Brazilian club are willing to sell, but only at the right price. "I want the transfer of Oscar to be the biggest transfer deal ever in Brazilian football," he told Radio Gaucha.
He continued: "The Chelsea offer isn't that far from that. Last year, however, Tottenham made two offers for Leandro Damiao. We kept him and he was very important.
"Oscar's situation is similar. If we get offers for Oscar that match our expectations, we'll negotiate. But they have to be of the value that mean significant resources for Internacional.
"But those values would be the biggest negotiation in Internacional's history."
Meanwhile, Florent Malouda's potential move in the opposite direction could be scuppered by the French midfielder's wage demands.
Santos head coach Muricy Ramalho is concerned by the financial outlay needed to sign Malouda, who has slipped down the pecking order at Chelsea.
"Malouda was offered to us. He's a very interesting player but you get scared when they tell you their demands," said Ramalho. "He was offered to us, but when you think about his wages, it gets hard.
"He is a very good player, an old-school midfielder who can hold the ball and set the tone in attack."