The injection of Lukhan Tui into the Wallabies backrow presents a fresh challenge for the Irish pack, with an increased output from the Pooper pair already expected by Ireland coach Joe Schmidt.
Tui has been called into the starting XV ahead of Caleb Timu for the tantalising Sydney decider, packing down with star pair Michael Hooper and David Pocock.
His inclusion will add some much needed go forward to the Wallabies pack but Schmidt highlighted Tui's defence - having thumped star prop Tadgh Furlong in the second half last week - as an asset which Ireland must nullify.
"I thought Tui did well when he came on (last week)," Schmidt said.
"He does give them a bit more in the lineout whether he comes on loose or whether he plays at lock.
"There was one time where Tadgh Furlong carried and I thought Tui hit him very hard."It's a bit hard to bring the farmer down but he fair stopped him."
Ireland did a far more effective job at the attacking breakdown in the second Test than they did in the first but Schmidt denied the changes he has made in the forward pack had anything to do with the collar they were able to put on both Hooper and Pocock in Melbourne.
"I think Pocock and Hooper had about 34 bites at the ball in the ruck - that's an incredibly high volume," Schmidt said.
"We know that they're going to be every bit as threatening in the ruck again.
"It was more about balancing our side than combatting an Australian threat that exists and that we know is going to be at the forefront on Saturday."
On the topic of Australian threats, Schmidt denied any illegality in the Irish ploy which stopped Israel Folau's aerial artistry in its tracks.
"I would leave it to you guys to have a look and see what you think," he said.
"I don't believe there is anything illegal going on there."Guys have every right to come back directly onside and we just worked a bit harder getting back, knowing that if Israel does win the ball, you have to get someone in behind it.
"Otherwise you are going to be in trouble.
"I've seen some fantastic footage of him in recent times taking a kick off and then running another 30 metres because he's so quick when he hits the ground.
"We have real urgency to get back behind the ball, to support that receiver and I have no doubt they will have the same urgency.
"That's part of the intensity that gets brought to a Test match."
One threat the Irish will not have to worry about is the work of Will Genia but Conor Murray wrapped Nick Phipps as a suitable replacement.
"Will's obviously a fantastic player and we have massive respect for him but Phipps was in the side a few seasons ago when he got a good run and started a few Tests and he was really effective for them," Murray said.
"He's a fit scrumhalf, he's going to be there throughout the game and I think he did really well against us in November a couple of years ago.
"I think he scored two tries and was the heartbeat of their side that day.
"Will is obviously a world class player but bringing someone like Nick Phipps in is going to add to the squad, definitely."
The Wallabies take on Ireland in the third Sydney Test on Saturday June 23, kicking off at 8:05pm AEST, LIVE on FOX SPORTS, Channel Ten and via RUGBY.com.au RADIO.