Wales manager Chris Coleman has said it would be "dangerous" if Real Madrid try to play Gareth Bale for a full 90 minutes on Saturday.
The 24-year-old is in line to make his debut for his new club against Villarreal, after appearing as a substitute for Wales, in their 3-0 defeat to Serbia.
Bale has been suffering with a foot injury, and then a groin problem. He came off the bench with just over half an hour remaining, and almost grabbed a goal with a free-kick.
Coleman said: "If he starts Saturday, he will not finish the game. I would be amazed if he does. We have looked at him in these 10 days and he is nowhere near ready for 90 minutes, even if Spanish football is slower. He has only had four training sessions in two months which is dangerous."
More top news
It's judgement day at the Millennium Stadium as Cardiff Blues take on the Ospreys and the Newport Gwent Dragons face the Scarlets.
Showers expected throughout the day especially in the north. Drier and brighter elsewhere but cooler than in recent days.
Most places will become dry overnight, although it will remain generally cloudy with patches of hill fog.