Gary Cahill has slammed Chelsea's performance in their 2-1 defeat at Crystal Palace on Saturday.
The Premier League champions fell behind to Cesar Azpilicueta's 11th-minute own goal before equalising seven minutes later via Tiemoue Bakayoko's header.
However, the Eagles struck back through Wilfried Zaha on the stroke of half time and went on to claim all three points, leaving the Blues captain feeling very bemused by the afternoon's events.
"The performance level today was not up to the standard it should be. We played poorly today, for whatever reason," Cahill told BBC Sport.
"We've had many international players who have been away but that's part and parcel of modern football. We need to be ready, we needed to be more lively, we were missing out on second balls. That's unlike us.
"We're not having the best of luck in terms of injuries - you saw Victor Moses today - and we've not got the biggest squad. But it needed to be a better performance today.
"We need to win games like this, and in terms of the title after Christmas we need to be there or thereabouts. We are disappointed by the result and disappointed in the quality of our performance."
Up next for Chelsea is a Champions League home encounter with Roma on Wednesday night.
