The 20-year-old, who will represent Brazil at the London Olympics, has chosen to move to Chelsea, who have made an offer of £20 million to Internacional.
While the bid is yet to be accepted, Oscar's agent Carlos Meinberg Neto says he expects a deal to take his client to Stamford Bridge to be completed.
"Chelsea did offer 25 million euros, but there is still no agreement between the clubs, that may happen in the next few days," Carlos Meinberg Neto told Terra.
"Giuliano Bertolucci (another agent who represents the player) will travel to England to finalise the remaining details.
"Tottenham also made an offer, but he should accept Chelsea's offer as there is more exposure there."
Oscar is a versatile midfielder who has won six caps for his country and during his time at Internacional has won two state titles.