Wales prop Aaron Jarvis will not play again this season after he suffered a knee ligament injury during the 33-10 defeat against world champions New Zealand on Saturday.
The Ospreys tighthead was carried off in the third minute and will now require surgery. Exeter-born Jarvis, who made his Test debut against Argentina earlier this month, has been ruled of Wales' RBS 6 Nations title defence, which begins in February.
Ospreys physiotherapist Chris Towers has confirmed the extent of Jarvis' injury, describing it as "significant".
Wales' autumn campaign, in addition to producing successive losses to Argentina, Samoa and New Zealand, has been riddled by injury setbacks.
Jarvis now joins his Ospreys and Wales colleagues Adam Jones, Alun-Wyn Jones and Richard Hibbard on the sidelines, while Newport Gwent Dragons flanker Dan Lydiate is also a long-term absentee.
Wales face Australia in their autumn finale on Saturday, with head coach Warren Gatland having delayed his team announcement by 48 hours while injuries are assessed.
Wing George North, centre Jamie Roberts, lock Ian Evans and flanker Ryan Jones are among those whose fitness Gatland is sweating on prior to the team being confirmed on Thursday lunchtime.
Towers said: "Aaron suffered a significant ligament injury to his right knee in the Wales versus New Zealand game.
"He is going to require surgery and will miss the remainder of the 2012-13 season.
"We are currently in discussions with specialists to establish the best surgical option and timing of the surgery to ensure the best outcome."