Mason Grady will miss the rest of Wales' Autumn Nations Series campaign.
The Cardiff wing suffered an ankle injury during the first half of Wales' 24-19 defeat to Fiji on Sunday.
The WRU confirmed on Tuesday that he's now been released from the squad, after a medical scan determined that he will need surgery.
Grady's early exit from the Autumn internationals also deals a blow to Cardiff as they gear up for the start of a busy December, which includes the pool stages of the European Challenge Cup and the traditional Welsh festive derbies in the URC.
He was replaced in error by fly-half Sam Costelow during last Sunday's defeat - when head coach Warren Gatland had intended to introduce scrum-half Ellis Bevan instead.
Wales are on a run of ten straight defeats in Test rugby going into next Sunday's clash with Australia in Cardiff, followed by the visit of world champions South Africa on 23rd November.
Grady's absence could open the door for Blair Murray - who scored on his international debut against Fiji - as well as Dragons' Rio Dyer, who was overlooked in favour of the Scarlets winger.
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