Robin McBryde has revealed some Welsh rugby stars have been "found wanting" during this week's training.
Grand Slam winners Wales have been beaten by world champions South Africa and New Zealand this month.
Wales forwards coach McBryde admits: "A few players that have been found wanting and they'll be told in no uncertain terms next week.
"They need to readdress the way they approach the game, their attitude and their professionalism."
McBryde's stinging criticism of his Wales players is a shock on the eve of their final autumn Test with Australia, the third southern hemisphere super-power to visit Cardiff this November.
The Welsh hope to end an autumn of southern hemisphere dominance and claim a their first Tri-Nations win for four years when the Aussies visit the Millennium Stadium on Saturday.
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Wales coach Warren Gatland, who secured a Six Nations clean-sweep in his first campaign, targeted a major scalp this autumn and the Wallabies were seen as arguably the best chance.
So McBryde's unprompted broadside at his Wales players is a little surprising.
"This week we have not taken the foot off the gas," he insisted.
"We've continued to challenge the lads and that has been reflected in the training sessions as they have been as physical and demanding as they were in the first week.
"We've kept on at them, we've been quite relentless in the way we challenged them both on and off the field.
"There have been a few players who have been found wanting and they'll be told in no uncertain terms next week."
Wales have recalled winger Mark Jones and lock Ian Gough while Australia have brought in Richard Brown, Phil Waugh, Mark Chisholm, Luke Burgess and Ryan Cross for their final 2008 Test.
As should Wales beat Australia, Gatland's men could make the top four seeds for Monday's World Cup draw if they win by over 15 points.
Should they achieve that landmark and if England lose to New Zealand at Twickenham on Saturday, Wales would take Argentina's fourth spot in the International Rugby Board rankings.
Wales: Lee Byrne (Ospreys); Mark Jones (Scarlets), Tom Shanklin (Cardiff Blues), Jamie Roberts (Cardiff Blues), Shane Williams (Ospreys), Stephen Jones (Scarlets), Gareth Cooper (Gloucester); Gethin Jenkins (Cardiff Blues), Matthew Rees (Scarlets), Adam Jones (Ospreys), Ian Gough (Ospreys), Alun Wyn Jones (Ospreys), Ryan Jones (Ospreys, capt), Martyn Williams (Cardiff Blues), Andy Powell (Cardiff Blues).
Replacements: Richard Hibbard (Ospreys), John Yapp (Cardiff Blues), Luke Charteris (Newport Gwent Dragons), Dafydd Jones (Scarlets), Martin Roberts (Scarlets), James Hook (Ospreys), Andrew Bishop (Ospreys).
Australia: Drew Mitchell (Western Force); Peter Hynes (Queensland Reds), Ryan Cross (Western Force), Stirling Mortlock (Brumbies, capt), Digby Ioane (Queensland Reds); Matt Giteau (Western Force), Luke Burgess (NSW Waratahs); Benn Robinson (NSW Waratahs), Stephen Moore (Queensland Reds), Al Baxter (NSW Waratahs), Mark Chisholm (Brumbies), Nathan Sharpe (Western Force), Hugh McMeniman (Queensland Reds), Phil Waugh (NSW Waratahs), Richard Brown (Western Force).
Replacements: Adam Freier (NSW Waratahs), Matt Dunning (NSW Waratahs), Dean Mumm (NSW Waratahs), George Smith (Brumbies), Sam Cordingley (Queensland Reds), Quade Cooper (Queensland Reds), Lote Tuqiri (NSW Waratahs)/Adam Ashley-Cooper (Brumbies).
Referee: Allan Lewis (IRFU)
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