Williams suffered the setback on Sunday as his Cardiff Blues side were edged out by a star-studded Asia Pacific Dragons outfit in their final fixture at the National Stadium.
A Cardiff Blues statement read: “Owen Williams is to remain in hospital in Singapore after sustaining an injury at the World Club 10s. Williams was injured during the first half of the 3rd/4th play-off fixture with Asia Pacific Dragons on Sunday afternoon.
“The region would like to take this opportunity to thank fans for their messages of support for Owen. Cardiff Blues will issue further updates when they are available.”
The 26-17 defeat to the Dragons was halted for some time while Williams received treatment and, while the severity of his injury has yet to be confirmed, the 22-year-old hasn’t travelled home with the rest of the Blues squad.
The news is a bitter blow for the Aberdare product after his season was disrupted by hamstring problems that saw him limited to just nine games for the Blues.
That setback came after a promising start to the campaign in which he built on his summer debut for Wales in Japan and scored a stunning, solo try in the November win over Tonga at the Millennium Stadium.
