Australian openside Michael Hooper says the British and Irish Lions will sorely miss lock Paul O'Connell due to injury.
O'Connell will miss the remainder of the Test series after breaking his arm in the latter stages of the first Test in Brisbane.
Waratahs flanker Hooper, who is facing the Lions for the first time, admitted that O'Connell left a big impression in the first Test and that the Lions would miss his influence.
"Paul's an intimidating figure when you see him standing across from you in a lineout," said Hooper.
"He attracts a lot of attention. He'll be a big loss to their camp and it's a shame.
"He finished the game with a broken arm so you can see how much he wants to be there.
"There will be someone who steps in who is just as good. Maybe they won't bring the same emotional or spiritual thing that he'd bring, but skill-wise it will be the same."
Hooper added that the lack of punishment against James Horwill, after the Wallaby captain was cited for stamping on Alun-Wyn Jones, was also a big boost for Australia.
"It was great to keep our skipper. He's a massive motivational part of our team," added Hooper.
"We get a lot of drive from him in the words he says and his presence on the field.
"We know that O'Connell was a big player for the Lions, very similar to Horwill."
Hooper also added that the Wallabies were more than aware of what was at stake ahead of the second Test in Melbourne, looking to emulate the 2001 series when the Wallabies came from behind to win the Tests 2-1.
"We're brown bread you could say if we lose! It's do or die for us now, there's no buffer," stated Hooper.
"We wanted to win every game. That's not realistic now, but we'd be happy with a series win.
"It would be really exciting if it came down to a series decider. We have to put everything into this weekend, it's huge for us.
"We put ourselves in a position to win at the weekend and we need to do that again."