Rhys Williams will have an x-ray on his left foot on Monday following an injury sustained in Friday's match against Stade Francais Paris
The full-back's first game as team captain ended painfully when he was forced to leave the field in the 53rd minute. The injury is just above the ankle but a further assessment of its extent will be made on Monday.
The Blues' next Heineken Cup match is against Ulster who will retain hopes of further progress in the competition when they play at the Arms Park next Sunday, 16 January (3.00pm)
Meanwhile, the team management have confirmed that Jamie Robinson requires knee surgery that will probably sideline him until the beginning of next season. Director of rugby David Young said, "This is obviously disappointing for Jamie and the team but we have to take a long term view. There was no guarantee that a further programme of rehabilitation will work and, in the long run, surgery now will be the best way forward."
Nick Robinson joined the squad for training last week and is on course for a return to match action when the Celtic League campaign resumes after its Six Nations' break in February. The Blues do not have a fixture between 28 January and the first weekend in March.