By SABC Sport
20th September 2023
Eddie Jones' team are teetering on the edge of a World Cup pool stage exit for the first time in their proud history.
If Wales beat them in Lyon, then their quarter-final hopes will be over and head coach Eddie Jones left to face the music.
"It is a cliche, and I apologise, but you just have to focus on yourselves," Thomas said.
"When you start thinking about permutations or selection of the opposition, you go down a rabbit hole, in my opinion.
"Confidence, for me, comes from the work you do during the week. That is where we get our focus from.
"We respect Australia as a rugby nation. They are a wounded animal, they can be dangerous."
Australia hold a 5-2 lead across the countries' seven previous World Cup meetings, but Wales will start as favourites this time around.
They have collected a maximum 10 points from their first two Pool C games - a record that only Ireland of any other team in the competition can match.
Wales' pool stage win against Australia in Japan four years ago set them on a course to the semi-finals, where they were knocked out by South Africa in Yokohama.
Wales centre George North added: "I've been to quite a few World Cups now, and to get early results is good.
"I think if you had said to us we would have 10 points after the first two games, I think everyone would have bitten your hand off. It is a massive game that we have to go and win on Sunday.
"The quality we have got now is really showing. Each day everyone is trying to get better to fight for that jersey and that's what drives you on.
"It (qualifying on Sunday) would certainly be a little weight off the shoulders, wouldn't it? What has stood us in good stead is just focusing on every game as it comes.
"We will have had an eight-day turnaround, which helps, from the Portugal game. We've had that rotation and allowed everyone to have a game.
"The families have been out and we've seen them. Every week, we have a day off, and that ability to switch off is key. I think it has really showed.
"This week, boys are really chomping at the bit. Yesterday was what we would call a recovery day, but it was far from recovery. It was very much on full gas.
"I think if we can keep pushing that today and the rest of the week, it will put us in a great position come Sunday."
Wales head coach Warren Gatland's team selection looks unlikely to deviate far, if it all, from the one that defeated Fiji in Bordeaux 10 days ago.
He could, though, decide on naming two specialist openside flankers in the back row, with Jac Morgan and Tommy Reffell starting alongside number eight Taulupe Faletau.
Reffell was due to feature against Portugal, but a tight calf muscle saw him withdrawn from the starting line-up just before kick-off.
Thomas said: "It was a prudent move not to play him. He is being assessed every day. He is the only one we will weigh up - everyone else is fit.
"The good thing we've got with our back-rowers is that they are versatile. All of them can play in different positions, pretty much, so those options are always there. We will see."