Lions loosehead prop Wyn Jones may have to cover tighthead against Australia as Wales face up to a front row injury crisis.
WillGriff John is set to miss out after taking a bang to the head against Fiji, while Tomas Francis is also a doubt after suffering concussion ahead of the game.
As for those tightheads with Test experience who could, in theory, be called up to the squad, Samson Lee and Leon Brown are both out injured.
So that leaves Dillon Lewis, who himself is only just back from a foot problem, as the only fully fit specialist No 3.
As such, Wyn Jones is on standby to cover tighthead should Francis and John both be ruled out, with Lewis then the man to start in the scrum cornerstone position.
Meanwhile, lock Will Rowlands is set to miss out after a HIA, so it will come down to a choice between Seb Davies and rookies Ben Carter, Christ Tshiunza and Rhys Davies as to who should partner Adam Beard in the second row.
It’s hoped that wing Josh Adams (calf) and No 8 Aaron Wainwright (shoulder) will be fit to face the Wallabies, although a decision will be left until late in the day.
The same goes for Tomas Francis, leaving the propping situation up in the air.
Forwards coach Jonathan Humphreys said: “We’ve had Wyn Jones who covered tighthead in the last World Cup, so we would be in that situation if it comes that way.
“The people outside who could possibly be called in are all injured as well.
“It’s one of those. It’s a testing time.
“In terms of resources, we’re probably as deep as we can go.
“It is what it is. I’m sure we’ll find a way to find a way to fight our way out of it.
“In regards to the two HIAs (Rowlands and John), they are following protocols but it’s unlikely they are going to be right.
“Tomas Francis is again following protocols. We are a bit more hopeful on that.
“Hopefully Josh Adams is going to be right. It will probably be a last minute clearance on that, but hopefully he’s going to be right.
“With Aaron Wainwright, it’s going to be a late call on it, but he’s made significant improvements so hopefully he will be involved.
“There’s not been a lot of physical stuff, his call will be made late on in the week.”
Humphreys added: “The tanks right now are low, but I know come the weekend we’re going to be right and be ready for the fight against one of the best teams in the world.”
On who will captain Wales against Australia, Humphreys said: “I think that’ll come down to selection.
“If Jonathan Davies is in the team, then there’s a high probability he will captain it.
“If he’s not in the team and Ellis Jenkins is, then he’ll captain it.
“It will come down to selection and how Wayne and Stephen want to go with the back-line.”
As it happens, the Wallabies have also faced a tighthead crisis on tour, with both Allan Alaalatoa and Taniela Tupou suffering from concussion, meaning loosehead James Slipper having to start at No 3 in last week's defeat to England.
It remains to be seen whether either Alaalatoa or the giant 20st 11lbs Tupou will be fit to return against Wales.
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