Very little is known about the nature or extent of Owen Williams' injury, sustained whilst playing for Cardiff Blues against Asia Pacific Dragons in the World Club 10s on Sunday.
The Blues released a statement yesterday, saying: "Owen Williams is to remain in hospital in Singapore after sustaining an injury at the World Club 10s. Cardiff Blues will issue further updates when they are available."
Blues teammate Macauley Cook also tweeted yesterday to say he was at the hospital with Williams, waiting for his family to arrive.
The WRU said 22-year-old Williams has not travelled home with the rest of the Blues squad.
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Today will be dry for most with plenty of sunshine, but also a fresher breeze than recently.
Generally cloudy with fairly persistent rain through this evening, but the cloud and rain will break up overnight with drier conditions.
Wales fans are continuing to celebrate yesterday's historic Euro 2016 win over Northern Ireland, which sees them make the quarter finals.