Jose Antonio Reyes has suffered another injury setback, just as he seemed set to return for Real Madrid.
Reyes fell awkwardly on his shoulder in training on Thursday and was immediately rated doubtful for Sunday's match against Osasuna.
Reyes has undergone an initial examination and more extensive tests will be carried out on Friday.
The news is a setback to Reyes who had only just returned to full training.
A knee injury has restricted the Arsenal player's participation in recent weeks as he bids to re-establish himself at El Bernabeu.