Chelsea midfielder Oscar has told his teammates that they must respond quickly after their shock defeat in the Champions League.

The Blues lost 2-1 to Swiss champions Basel in their opening match of Group E on Wednesday, having led at the break thanks to the Brazilian's opener.

"We played well in the first half and at the start of the second, but we conceded a goal that destabilised the team and then fell behind," Oscar told reporters.

"It happens, but we do have to make up for it in the next game with a win. The system worked well today, but the ball just would not go in the net; we hit the bar, [Eden] Hazard went close. We had plenty of chances to make it 2-0 but ended up losing."

The loss marks Chelsea's worst start to a season under Roman Abramovich.