After their loss to Fiji, the game is do-or-die for the Australians in their hopes of making the quarterfinals.
Halfback Tate McDermott said: "We don't want to play footy in our half, and that's generally every team who thinks that way.
"We've got to be a lot smarter with those kicks because against a team like Wales, all you do is give them possession.
"So, you've got to make it a contest. If it's not a contest, or if it's not going into touch, you're essentially just handing them the ball and a team like Wales will make you pay for that."
England's captain and first five-eighths, Owen Farrell, will make his first appearance of the Rugby World Cup against Chile at the weekend.
Having completed a ban that denied him appearances in the first two games against Argentina and Japan, he has replaced George Ford. Farrell told the media he had struggled as a spectator.
"It's been tough not playing, but it's been brilliant to see what the lads have been doing on the pitch.
"I'm knackered [after games] by the end to be honest, especially that first one [the win against Argentina]. I wouldn't say I'm a good watcher. I feel involved, like I'm out there at times."
Farrell said missing games was a challenge because he wanted to be playing.
"I was glad I was able to still train, it's not like being injured where you're on the sidelines. I was still part of the group, which was good.
"I probably get a different perspective [from the stand] but I want to be out there on the grass. It's been good to have been involved in training over the past few weeks but I'm looking forward to being able to play."
Ireland coach Andy Farrell is looking forward to his side's game with South Africa on Saturday.
"We have to be good and play really well to beat the world champions because they are in good form. Barring us, our team, management, and the Irish people worldwide, everyone thinks they're the favourites and will win this game.
"I can see why because of the form they've shown in the last couple of games. But we don't think like that. We are ready for a tough battle.
"It is not a must win, it is not a do-or-die game, but it is pretty important to both teams, let's put it that way. It's always nice to win but we have always looked at ourselves mainly in terms of performance. It's a big game, there will be over 30,000 Irish supporters in a stadium we know well. We want to get back to winning ways there, so it is a challenge we are ready for, looking forward to and it is coming soon."
Former New Zealand Super Rugby player Bundee Aki will play his 50th Test.
"It's a huge occasion but I'm trying not to treat it as a big occasion. It's a huge honour to pull on the jersey 50 times. I don't take it lightly. Every time you put on that the jersey, you try to play the best you can and put your best foot forward."
Playing 50 Tests was never on his horizon when he set out to play in Ireland.
"No, not a hope. To be able to get to 50 is probably like getting to 100 [for someone else]. Fifty is a big number, and I know how hard it is to get to 100. I'm just quite lucky to be able to put on this jersey for a 50th time and I'll look forward to it."