The two teams will clash in the first encounter of a three-Test series in Brisbane on Saturday, with the Wallabies' last serious match coming in December 2012.
However, Genia is adamant that head coach Robbie Deans has done the right thing by keeping the men in gold in camp.
"It comes down to preparation. We have been lucky enough to have two weeks build up to this test and we've taken the opportunity to bond well as a team in every training session," Genia told the official Lions website.
"We have really focused on buying into the way we want to play and preparing as well as we can to be as sharp as we can. We have played together previously a number of times and, even though there are different combinations, we are all very familiar with the way we want to play because it hasn't changed too much over the years.
"We have had stability within the coaching group and the senior players in the squad have been together for a long time. We are the best prepared we could possibly be and that's all we can do."
The first Test gets underway in Brisbane at 11.05am.