Improved ball control and a better defensive mindset have been crucial to the Warriors' improving form but they face yet another big test against one of the competition's true heavyweights.
With Queensland State of Origin star Greg Inglis at fullback, captain John Sutton at five-eighth, and a hulking pack containing Ben Te'o and the Burgess brothers, Sam and George, the Rabbitohs have size and power right across the park.
McFadden believes the Warriors' challenge is clear-cut and knows what his side has to do.
"Maintaining that completion rate is going to be important because they're obviously a big physical side so if we give them a lot of possession that will play into their hands," he said.
"Holding the ball and trying to starve them of possession and even winning the possession count is going to be critical to beating them."
The Warriors forwards, led by front-rowers Suaia Matagi and Jacob Lillyman, have the muscle to match the Souths pack, but it would be a mistake for them to get locked into a physical battle when they possess plenty of strike-power on the edges and wider out through the backs.
Both teams arrive in Perth having won four out of their last five matches but the Warriors are looking for a change in fortune after defeats in their previous two visits to Western Australia.
Despite a good build-up, they went down in last year's encounter against Souths (13-30), while a late collapse against Manly saw them lose (22-24) in 2012.
A rethink saw the Warriors e travel a day earlier this time, making the long-haul flight on Wednesday, but McFadden believes they need to learn from their mistakes.
"That's just designed to help us adjust to the time difference and help us get over the flight really," he said.
"Our preparation last year was really good. We certainly had a lot of energy and our performance was good although we lost the game. We're going to try to mirror that as much as possible because our energy levels were good.
"That's always the concern when you travel is how you get them up physically." Despite the arduous journey and their poor record in Perth, the Warriors can count on having strong support at NIB Stadium, with a loyal following of ex-pats expected to once again turn out in force.
"Last year there was probably 20-plus thousand and I reckon three-quarters of them were Kiwis and it was nice to have the home crowd chant."
Hooker Nathan Friend echoed McFadden's enthusiasm, recalling how the team received a huge turnout at their last training run. "We've got massive support there. We got to a session on the day before the game for our captain's run and we had around 2000 people there. It's not what you get every weekend and you've got to love the passion of the supporters over there."
The Warriors' consistent performances over the past month will see them field an unchanged line-up, while some exciting one-on-one battles loom at halfback, with Shaun Johnson facing off against Adam Reynolds, and at hooker, where Kiwis test rake Issac Luke's creativity contrasts with the workhorse nature of Nathan Friend.
Two England teammates will also enjoy testing themselves against one another, with the two Sams, Tomkins and Burgess, opposing each other for the first time in the NRL.
