The Brazilian centre-back took to social networking website Twitter to explain that he has been forced to pull out of the Blues' second league game of the season.
"Good morning #geezers!" he wrote. "I'm a bit sad today, because I can't play tonight, I have a pain [in] my knee".
|A MAJOR LOSS?|
|3/1||Reading are 3/1 with William Hill to score the first goal against Chelsea|
The former Benfica stopper is entering his second full season as a Chelsea player after arriving in January 2011 for €25 million [£20m].