Wales centre Owen Williams "suffered a significant injury to his cervical vertebrae and spinal cord", announced Cardiff Blues on Wednesday.
The Welsh region released an update on Williams' condition following his serious injury in the Singapore 10s competition.
"Cardiff Blues have confirmed that Owen Williams has suffered a significant injury to his cervical vertebrae and spinal cord," read the statement.
"He underwent an operation on Monday to stabilise a fracture and is currently recovering in hospital in Singapore.
"The family of Owen Williams are now at his bedside along with senior Blues management and medical staff.
"Arrangements are currently being made to co-ordinate his safe transfer home at an appropriate time.
"Cardiff Blues and the Williams family would like to thank the many hundreds of well-wishers who have offered messages of support.
"Cardiff Blues will be making no further comment, but will continue to share further updates when they are available. We would also ask that the privacy of Owen Williams and his family is respected at this time."
The rugby world have sent thousands of messages of support to Williams and his family since the news broke, using the hashtag #StayStrongForOws.