That scenario will unfold, though, for last season's World Cup semi-finalists and RBS 6 Nations champions if they lose to Australia at the Millennium Stadium next Saturday.
A fourth successive home defeat of the autumn campaign would also see Wales drop out of the world's top eight-ranked teams and into tier three for next week's 2015 World Cup pool draw.
They have lost seven Tests in a row to Australia, but four of those reversals were by six points or less.
"Next weekend means everything," said Shingler, who replaced an injured Bradley Davies just three minutes into Wales' 33-10 defeat by world champions New Zealand on Saturday.
"Everything is on the line. It's important we don't come away with four losses. It is a massive, massive week ahead.
"We've got to be very accurate, very aggressive and look to bully them (Australia).
"A whitewash is almost unthinkable. We've trained well every week, our preparation has been good, it just hasn't gone as we would have liked on the field."
Injury worries that have stalked Wales since before the autumn internationals began when prop Adam Jones and flanker Dan Lydiate were sidelined by long-term problems, remain an issue.
Tighthead prop Aaron Jarvis injured his knee against New Zealand and left the Millennium Stadium on crutches, while centre Jamie Roberts suffered hip trouble and flanker Ryan Jones was concussed.
Another prop, Bath's Paul James, and Perpignan-based utility back James Hook are unavailable because the Australia game falls outside the International Rugby Board's autumn Test window and clubs are under no obligation to release players.
France-based trio Mike Phillips, Gethin Jenkins and Luke Charteris are all available, though, after an agreement was reached between the Wales management and their respective clubs.
Having lost to Argentina, Samoa and now New Zealand this month, which followed a 3-0 summer Test series defeat in Australia, Wales are experiencing their worst run of results since the 2002-03 season.
Wales hooker Matthew Rees said: "It's a massive game next week and we have got to win. At the end of the day, international rugby is all about winning.
"We knew it was going to be a tough ask against the world champions, but we had a good week of preparation and thought we had enough to get the result.
"But we know how clinical the All Blacks are and how good they are individually.
"We came second best, but one thing this team will not do is lie down."
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