A WRU spokesman said: “Alex Cuthbert sustained a knee injury in Cardiff Blues’ final training session ahead of their fixture against Toyota Cheetahs last weekend.
Following subsequent scans and a review with his Orthopaedic consultant, Cuthbert will undergo surgery with a 4-6 week return to play-time frame.
With this in mind he will remain at Cardiff Blues for his medical management and will be released from the Wales national squad.
Â