The match kicks off at 12.10am BST on Sunday.
Roncero has been a cornerstone of Argentinian rugby for 14 years and he has appeared in three Rugby World Cups, including the Pumas' third place finish in 2007.
The 35-year-old has tasted victory over all the Six Nations teams - but to sign off with a win against the Wallabies would be the crowing glory of his career.
Roncero announced on Thursday that this will his 55th and final match for Argentina - and he has never had a better chance to claim the major southern hemisphere scalp he craves.
"I retire content, the Pumas jersey gave me some of the best moments in my life," Roncero said.
"Looking back, my career has been extremely positive. I played at three World Cups and I managed to play the first Rugby Championship.
"I'm just missing the plum of beating one of the three powers (New Zealand, South Africa and Australia)."
Argentina drew their first home match with South Africa and came close to beating the Wallabies on the Gold Coast, leading 19-6 before falling to a late Australia comeback.
The Wallabies, meanwhile, are ravaged by injuries.
Robbie Deans has had to make five changes from last weekend's 31-8 defeat to South Africa in Pretoria and he decided to try and match the Pumas physicality.
Mike Harris will start at full-back and Ben Tapuai comes into the centres to win his second cap after Berrick Barnes and Adam Ashley-Cooper were injured at Loftus Versfeld.
The Wallabies are already without David Pocock and Will Genia plus Quade Cooper, who has heaped the pressure on coach Robbie Deans with claims that the environment in the Australia camp is "toxic".
Nick Cummins will become the 11th Australian debutant of 2012 when he starts on the wing in place of Dominic Shipperley while flanker Sitaleki Timani and prop James Slipper also start in an inexperienced side.
Australia's starting XV has the combined total of 345 Test caps - 110 of which belong to the captain Nathan Sharpe.
"We know that the Pumas will be coming straight at us, and will be looking to profit in the collision in the same way that the Springboks did last week," said coach Robbie Deans.
"We've addressed that, both internally in our discussions, but also with our selection, where we have gone for the players we feel are best suited to that approach."
Pumas coach Santiago Phelan has retained the same starting line-up that was beaten by New Zealand last week, while Leonardo Senatore and Nicolas Sanchez come onto the bench.
Gilbert has released a new line of rugby cleats. The Gilbert Virtuo 8S is part of the exciting new product. Check it out.
The entire All Blacks apparel line has been updated for 2013/14. Check out the New Zealand All Blacks polo.
The Nike Tiempo is a solid rugby cleat and one of few styles still made from full-grain natural leather.
The Gilbert Blitz 8S rugby cleat is a great cleat at a great price of $69.99. Get a new pair of cleats today.
A cool looking all black rugby cleat with the high performance adidas is known for. Get in the Gear!
Wear the crest of the British and Irish Lions on your t-shirt. A great look for the summer.
The All Blacks Performance t-shirt is black with hints of blue from the training jersey. Very Cool.
The New Zealand All Blacks training jersey for 2013/14. Get in the Gear!
The USA Rugby Pro Alternate rugby jersey is perfect for any fan of the Eagles. Get yours to wear during the summer Test matches.
The NEW All Blacks 2013/14 jersey has arrived at World Rugby Shop. Dare to wear the colors of the All Blacks.