Chelsea have denied reports that Oscar has been the subject of a £75m bid from China Super League club Jiangsu Suning.
The speculation came days after the side paid the Blues £25m for Ramires and follows big-money moves to bring Jackson Martinez, Alex Teixeira, Demba Ba and Gervinho to China.
Speaking ahead of Chelsea's game with Manchester United, interim manager Guus Hiddink said of Oscar: "Well we know that just Ramires had a great offer. Oscar for me is just speculation. We do not go into that."
Hiddink admitted that the spending power of China was a "concern" as the nation looks to rival the success of the Premier League.
"It's a concern. It shows China is very serious to get into international football. They are very serious about their reputation," he told reporters.
"I had some contacts over there and they agree you cannot just buy star players for big money and think you have to have grounded Chinese football. They want obligation football in schools and universities and to also hire people that can give educations."
The Chinese transfer window remains open until the end of February.
Neil Wilkes
