Real Madrid defender Ricardo Carvalho has suffered a fresh injury in training after he twisted ligaments in his right knee.
The 33-year-old has been out since September with a back injury he sustained against Ajax in the UEFA Champions League.
Real have given no indication of how long the former Chelsea stopper will be out of action after this latest blow.
However, in his absence, Sergio Ramos and Pepe have flourished at the heart of the defence.
Meanwhile, Cristiano Ronaldo missed his second training session of the week with a sprained ankle.
The forward picked up the injury in the derby win over Atletico Madrid last weekend and is trying to ease his way back to full fitness.