The Wallabies won the first test in Brisbane 18-9, but had issues with their lineout with hooker Brandon Paenga-Amosa making his debut.
Their loose forward trio of Hooper, David Pocock and Caleb Timu are also comparatively short and do not give them an additional lineout option.
Ireland have also strengthened their lineout for the clash at Melbourne's Rectangular Stadium with the 2.10m-tall Devin Toner being brought in for Iain Henderson, who is 1.98m.
"It's such a huge area of the game," Hooper told reporters on Friday. "We think we can get better in the scrum, and we definitely can get better in the lineout just with our sharpness.
"So, we spent a good amount of time (on the lineout) without getting too bogged down."
While rain is forecast for Melbourne on Saturday, which could result in a predominantly kick-oriented game plan from both sides, Hooper said he was keen for Timu to get his hands on the ball more, particularly in the wide channels to give his side greater momentum.
"He's such a threat with ball in hand," Hooper said of the 24-year-old, who also made his debut last week in Brisbane.
"It was Caleb's debut game so he was getting a feel for it.
"(I am) expecting him to understand the pace tomorrow and come out without those pre-game nerves to get his hands on the ball because he's such a threat."
Fellow loose forward Pete Samu, who is also a strong ball carrier despite a small size, will be called upon to do some of that work when he comes in off the bench.
The match will be a home coming for Samu, who was born and grew up in Melbourne but had to move to New Zealand to further his rugby career.
The 26-year-old Canterbury Crusaders player, however, was the subject of a public tug-of-war between New Zealand and Australia over his release for the series.
Samu made his debut off the bench last week in Brisbane and will get to play in front of '30 minimum' family members as Michael Cheika retained the same matchday squad for the first time in 46 tests.
"I never thought I'd be in this set-up playing on home turf," Samu said earlier this week.
"I haven't got around to the boys to ask for tickets but I definitely will; I'll probably need 30 minimum and I'm sure there will be a few more putting their hands up."
(Reporting by Greg Stutchbury in Wellington; Editing by Amlan Chakraborty)
