Cardiff Blues and Wales wing Chris Czekaj has undergone surgery on his broken right leg after suffering the injury in Wales' 31-0 loss to Australia last weekend.
Czekaj suffered the injury in the 22nd minute, twisting badly in a tackle by Wallaby hooker Stephen Moore.
The severity of the injury was immediatly apparent, and the 21-year-old was stretchered from the field in obvious distress.
Czekaj underwent surgery in Brisbane on Sunday and has been told he cannot fly home for at least 14 days.
The Cardiff Blues wing is almost certain to miss the Word Cup and could be out of rugby for up to a year.