Cory Hill has been released from Wales' Rugby World Cup squad after being unable to recover from a stress fracture of his leg.
The lock has not played since February after suffering an ankle injury during Wales' Six Nations victory over England.
Head Coach Warren Gatland selected Hill as part of the World Cup squad despite still being injured, but he was expected to be fit for Wales' second match against Australia.
The Welsh Rugby Union confirmed Bradley Davies, capped 65 times, has been named as his injury replacement and will arrive in Japan on Wednesday.
He's featured in two previous Rugby World Cup.
Wales, who opened their World Cup campaign with a 43-14 win over Georgia on Monday, had hoped that Hill would be available to face Australia in a Pool D showdown next Sunday, but he has run out of time.
Hill's fellow lock Adam Beard, meanwhile, only arrived in Japan three days ago after having his appendix removed.
Skipper Alun Wyn Jones and Jake Ball are set to continue as Wales' second-row partnership against Australia, with flanker Aaron Shingler providing lock cover on the bench.
Victory for Wales against the Wallabies would put them in pole position to top their group and book a possible quarter-final against France or Argentina.