Much speculation abounds about the make-up of the side to take on the Wallabies, but George North looks set to claim one of the wing berths after he was declared fit by backs coach Rob Howley.
The Wales winger sat out the tourists' last two games with the hamstring injury he suffered in the win over the NSW-QLD Combined Country team last week.
"I've not seen George in better physical shape. He has been icing his hamstring continually throughout the day, his whole focus has been getting himself right," said Howley, the former Wales and Lions scrum half.
"He was up bright and early this morning and came through a fitness test. It is a huge fillip and a real morale booster to have someone like him fit.
"It is completely different from other tours we have been on, the professionalism among these talented players.
"They are preparing for the biggest game in the calendar year and their diligence and professionalism can only be admired from within the camp. It shows how much they want to wear that red jersey."
If North starts, the other wing place will be between Alex Cuthbert, Sean Maitland and Ireland's Simon Zebo. Recent arrival Shane Williams' tour picked up a groin strain in Tuesday's defeat to the ACT Brumbies.
Jamie Roberts is unlikely to feature in midfield as he continues to nurse a leg injury with Manu Tuilagi reportedly 'touch and go' due to a shoulder problem.
That leaves Wales' Jonathan Davies poised to partner four-tour veteran Brian O'Driscoll in the centre, and goal-kicker supreme Leigh Halfpenny and half-backs Jonathan Sexton and Mike Phillips should complete the back-line.
The news on Tommy Bowe, who is working his way back from a fractured bone in his right hand, is that the Monaghan native should be fit for Saturday week's second Test in Melbourne.
England loosehead Mako Vunipola seems to have done enough over the first half of the tour to earn the number 1 jersey with Adam Jones nailed on for the tighthead spot, while Tom Youngs and Richard Hibbard are the leading candidates for the hooker role.
Paul O'Connell, the 2009 tour captain, is set to reprise his second row combination with Alun Wyn Jones from four years ago with English lineout specialist Geoff Parling providing back-up on the bench.
O'Connell is desperate to be part of a Series-winning Lions side and will use the 2009 third Test victory over South Africa as inspiration come this weekend.
"I was on the tour to New Zealand in 2005 and to this day it's still probably the toughest rugby experience of my life. I had this big expectation of what a Lions Tour was going to be and, unfortunately, I didn't play well," he admitted.
"A lot of us didn't play well and it was a very tough place to be after the tour. In 2009 it was a little different but, at the same time, it was a missed opportunity.
"For a lot of guys it's like the World Cup - it's your shot at forever, that kind of thing. If you can play well and produce a big performance who knows what can happen.
"I loved the last Test four years ago, the feeling and buzz we got after the win. Hopefully, we can produce something like that over the coming weeks."
Moulding a Test team together in such a short space of time is 'a big ask' according to O'Connell, although the recent Saturday wins over the Queensland Reds and NSW Waratahs have offered encouragement.
"The record of England, Scotland, Ireland and Wales against Australia over the last number of years isn't fantastic by any means. We've got a very tough three weeks ahead of us and we need to prepare to the best of our ability," added the Munster and Ireland lock.
"I think we can both assume and guarantee that from a physicality and intensity point of view it's going to be a big step up from last Saturday night against the Waratahs. I think we've done everything we can, but there's still more work to do.
"It's still a big ask to be taking on a southern Hemisphere team with only four or five weeks' preparation. For the first time I've been on a Lions tour there has been a lot of talk about it might be close to 50-50 or even making us favourites.
"That's something I find very difficult to comprehend because we've been together for only four or five weeks. It's very difficult to become a team in that time.
"Australia have been playing together a long time under this coach and the big challenge for us is trying to get up to Test standard four weeks into playing with one another."
The stiffest competition for starting places is in the back row where a number of combinations could slot in. Tour captain Sam Warburton is expected to start alongside Tom Croft and Jamie Heaslip, two players who combined to good effect in the Test series against the Springboks.
Should that trio be selected, that leaves Sean O'Brien, Dan Lydiate, Justin Tipuric and Toby Faletau battling it out for the reserve spot. The back row is a real embarrassment of riches for Warren Gatland and his coaching staff.
Rob Kearney, meanwhile, did well on his first tour start against the Brumbies and it would be no surprise to see him given the number 23 jersey for Saturday's Test opener.
Speaking after the 14-12 loss in Canberra, the Louth native, fully recovered from his hamstring tear, said: "I think this week was all about Saturday and it still is. Okay, it would have been nicer if we had won - it would have brought us some good momentum and there would have been a real high spirit amongst the camp within the boys - but I don't think it's going to affect us hugely.
"There were a lot of guys out there playing for the first time, it was a team that was pretty much put together over the last few days. But in saying that there were a lot of things we could have done better, that should be a given as professional rugby players.
"Of course we're always thinking about it (forcing a way into the Test team). This was my first start in six weeks so I just wanted to get some game-time under my belt and put in as best a performance as I could. It wasn't really a night for full-backs but that's the way it goes sometimes."
In South Africa four years ago, Kearney missed out to Wales' Lee Byrne who started the first Test against the Springboks at full-back. However, subsequent foot and hand injuries ended Byrne's tour and Kearney made the number 15 jersey his own, playing in all three Tests.
The Ireland international is adopting a similarly positive mindset as he looks to play his way into the starting line-up for the remaining games Down Under.
"Sometimes when you're least expecting a second chance you get it. There will be injuries as we've seen in every game, the attrition rate seems to be pretty high. So a lot of guys will get second chances," added the 27-year-old.
IRELAND'S 2013 LIONS - MATCH RECORD SO FAR:
Jamie Heaslip - 4 appearances/1 try/46 carries/177 metres/4 clean breaks/10 defenders beaten/28 tackles/8 lineout catches - (3 starts v Western Force, Combined Country, NSW Waratahs; replacement v Barbarians); 1 try v Western Force
Jonathan Sexton - 4 appearances/2 tries - (2 starts v Western Force, NSW Waratahs; replacement v Barbarians, Queensland Reds); 1 try v Western Force, 1 try v NSW Waratahs, 2 conversions v Barbarians
Conor Murray - 4 appearances/1 try/4 clean breaks/7 defenders beaten/3 offloads - (2 starts v Western Force, ACT Brumbies; replacement v Barbarians, Combined Country); 1 try v Combined Country
Sean O'Brien - 3 appearances/1 try/41 carries/10 defenders beaten/4 lineout catches - (3 starts v Western Force, Combined Country, ACT Brumbies); 1 try v Combined Country
Paul O'Connell - 3 appearances/1 try - (2 starts v Barbarians (captain), NSW Waratahs; replacement v Queensland Reds); 1 try v Barbarians
Rory Best - 3 appearances - (2 starts v Western Force, ACT Brumbies (captain); replacement v Combined Country)
Brian O'Driscoll - 2 appearances/3 tries/118 metres/4 clean breaks/5 offloads - (2 starts v Western Force (captain), Combined Country (captain)); 2 tries v Western Force, 1 try v Combined Country
Tommy Bowe - 2 appearances/1 try/4 clean breaks/8 defenders beaten/3 offloads - (2 starts v Western Force, Queensland Reds (hand injury)); 1 try v Western Force
Rob Kearney - 2 appearances - (1 start v ACT Brumbies; replacement v NSW Waratahs)
Simon Zebo - 2 appearances - (1 start v NSW Waratahs; replacement v ACT Brumbies)
Cian Healy - 2 appearances - (1 start v Western Force (ankle injury ended tour); replacement v Barbarians)
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