According to the Sport Review website, the 33-year-old centre-back limped off his side's goalless draw with Atlético in the first leg o on Tuesday after picking up a foot injury after an innocuous clash with Diego Costa.
"He won’t make this weekend and I don’t think he can make next week," said Mourinho.
"But let’s wait… He has a little chance (of making Wednesday)."
The Chelsea manager also confirmed that playmaker Eden Hazard will sit out the clash against the English Premiership leaders and is unlikely to face Atlético after missing the first leg with a calf strain.
"(Hazard is) out for Sunday and (for) Wednesday, let’s wait," Mourinho added.
Chelsea goalkeeper Petr Cech dislocated his shoulder in the draw at Vicente Calderon, whilst Samuel Eto’o picked up an injury in the final training session ahead of the trip to Madrid.
Furthermore, Mourinho confirmed that Chelsea’s injury situation remains the same.
"All of them injured… No (no-one is coming back)."