Chelsea boss Roberto di Matteo won't rush Oscar's introduction.
After playing yesterday's Olympics men's final at Wembley, the 20-year-old will remain on international duty for his country's friendly against Sweden on Wednesday before returning to his new club.
Di Matteo said: "Then we'll assess him and see how he is. We'll take it from there.
"It's too early to say which game he will be involved in."