Chelsea boss Jose Mourinho says Oscar is a doubt for Sunday's match against Manchester City after picking an injury in training.
Goalkeeper Thibaut Courtois will serve a one-match ban after the Football Association rejected the appeal for his sending off against Swansea City last week.
Meanwhile, the Portuguese reassured the fans that new signings could be made before the end of the transfer window.
"Oscar is a doubt, he had a little injury in training," Mourinho said on Friday.
"[Thibaut] Courtois is suspended as you know, and apart from that all [is] good.
"[Transfers?] First of all the transfer window isn't closed, it's open until 31 August.
"Secondly, you don't always have to be a champion in the market.
"And thirdly, we do things when we think we have to do them, when we think we can do them, and when we think it's the right moment to do them. Sometimes you have to think further ahead than the moment and many times we don't explain anything publicly because we work inside.
"The owner is the owner and will be for many, many years. The board has such a close relationship with the owner. The board just gave me four years contract so we are in great stability and we work fantastically well."