And despite a widespread suggestion that the Australian pack and their front row in particular is potentially their Achilles heel, there certainly won't be any sense of complacency from Rowntree and co.
"I keep saying this every time we play Australia: I've never fallen for this belief that they've got a weak front row," said Rowntree, after he joined Rob Howley and Andy Farrell in Gatland's coaching staff for the 10-match tour of Hong Kong and Australia.
"Yes, we've had some good games for England against Australia as a forward pack, particularly in the scrum, but they're a wily group.
"It's never an easy day in the office against Australia, regardless of reputations or what we've done the week before, the month before or the year before.
"Australia know how to win games. They're very experienced. They know about dealing with pressure and expectation.
"You look at that their front row that played against England at Twickenham - Benn Robinson, Tatafu Polota-Nau and Ben Alexander - they've got nearly 200 caps between them."
That experience was crucial at Twickenham a month ago as the Wallabies bounced back from a heavy defeat to France by seeing off Rowntree's England at HQ, while starting hooker Polota-Nau and his replacement Stephen Moore also caught his eye once more.
Alexander was particularly impressive upon his return from injury that day, producing a fine performance that simply cemented Rowntree's respect for his talents.
"Alexander's a fine prop," added Rowntree.
"They brought him back in for the game against us at Twickenham. I've been a big admirer of Ben for many years. He's a converted loose head to tight head, which is not an easy transition to make, and he brings a lot of experience and an incredible workrate to that pack.
"He's multi-skilled as a prop forward so I'm a big fan of his.
"(Stephen) Moore and Polota-Nau both seem to be starting as many games as each other and then you can bring the other one off the bench and they both make a huge impact. Again, they both bring significant experience."