The Wallabies have six days to work out "how to get something going" or risk having the green shoots they sowed on home soil shriveling up on what has fast become a disappointing tour of the United Kingdom.
Saturday night's 32-15 defeat by England was perhaps the most deflating Australian loss of the season to date, purely because the Wallabies never seriously threatened England's line and seemed bereft of ideas of how to break down the hosts' defence.
As the clock turned past the hour mark, it was hard to recall a sequence in which the Wallabies had strung four phases together, yet, 10 minutes later, they were still somehow in the contest, down 22-15.
The final 17-point margin was a far better reflection of the encounter, which gave England an eighth straight win over Australia and maintained Eddie Jones' unbeaten record against his old side.
It's true, as Jones noted post match, the Wallabies have been away from family and friends for months on end and, as such, deserve credit for the character they showed to hang in the contest. But if Australia are serious in their desire to mix it with the game's elite teams, both at home and away, their discipline, accuracy and execution requires significant improvement.
While Hunter Paisami was one of Australia's better performers, his long floated pass to Kurtley Beale that drifted up on the Twickenham breeze and was promptly grassed by the fullback was in some ways emblematic of Australia's evening.
On the very few occasions when it looked like the Wallabies might get something going, a poor or pushed pass, loose carry or aimless kick quickly saw the play break down before it had really even begun.
The final insult came on one such occasion when a promising move down the right touchline in the shadows of fulltime broke down with an intercept pass to England's Sam Simmonds, who then set replacement hooker Jamie Blamire on a 40-metre run to the line to send the Twickenham faithful delirious.
"Just couldn't get anything going, we got hammered in the penalty count, I think the possession and territory stats were in the 60s in favour of England and they choked us down there," Rennie said when asked to assess his team's performance. "We just made too many errors and dumb penalties that put us under pressure, so frustrating.
"There was a lot of character shown tonight, half time we hadn't had a lot of ball or territory but at 16-12 we'd fought hard. I just felt that if we could string a little more phases together we could put them under a bit of heat.
"But not accurate, not good enough tonight."
At the top of Rennie's to-do list this week will be addressing the team's discipline, as not only did Australia find themselves on the wrong side of an 18-9 penalty count, but both Tom Wright and Angus Bell were yellow-carded for dangerous tackles.
Having dropped their last three Tests at Twickenham and seven in total to Jones' team, the Wallabies could ill-afford to play with 14 men for 10 minutes, let alone 20.
Wright's tackle, while clumsy was forgivable, given England hooker Jamies George late change of direction brought the two players front on with one another. Still, Wright must better drop his bodyheight.
Bell's tackle was completely needless, however, and if Courtney Lawes had come down on his shoulder rather than his arm, Bell would have seen himself with a red instead of a yellow.
In terms of the penalty count itself, Rennie had few qualms with referee Jaco Peyper's officiating and bemoaned his side's inaccuracy at the contact area across the board.
"We were pretty frustrated with some of the penalties last week, but we're not going to complain about Jaco's refereeing," Rennie said. "I thought he controlled the game well and most of our issues were our own undoing. We got ourselves in good position with ball and we got stripped I think three times; we've got to be better."
It's clear Australia are struggling to fill the gaping hole left by Samu Kerevi, and to a lesser extent Quade Cooper. The lack of go-forward, which Kerevi was providing in midfield while also drawing in multiple defenders, which in turn opened up space elsewhere, has been telling.
The Wallabies certainly have some options at their disposal should Rennie try to jumpstart his team's stuttering attack. Tate McDermott, again, only enjoyed limited minutes off the bench while Izaia Perese may also be worthy of a start either in the midfield or on the wing; Len Ikitau has certainly shouldered a heavy workload in what is his first season at Test level.
It may also be time to hand Will Skelton a start. The La Rochelle lock has had a little impact off the bench over the past two weeks, and if the Wallabies are serious about seeing whether he is worthy of inclusion in the run to, and at, the World Cup, he should be given more time to throw his huge frame around.
Rennie also said he was confident both Allan Alaalatoa and Taniela Tupou would have recovered sufficiently from their bouts of concussion to feature against Wales.
But skipper Michael Hooper could be a doubt for the Cardiff finale, the champion flanker picking up a foot injury that saw him depart Twickenham on 53 minutes. For a man so used to going the full 80, the frustration on Hooper's face was painful to watch.
All in all, it was just a disappointing night out in south west London.
The Wallabies' record now sits at 7-6 for 2021. Sure, that is better than the 1-2-3 return from Rennie's first season in charge, but having strung five straight wins together through September and October the momentum was there to really push on and consolidate this season's progress.
Instead, the Wallabies' game has ground to a halt, the team getting a reality check as to how much more work is still to be done.
While the margin between the world's top seven or eight nations may be as narrow as it's ever been, evidenced by Ireland's pulsating win over the All Blacks, Australia have clearly been off the pace and second best over the past two weeks.
"Of course it's a setback, because the plan was to come over here and keep building on that [five-game winning streak]," Rennie said. "We haven't performed with the accuracy and consistency needed over here, they ask a lot of questions of you, they put a lot of ball in the air and they play a lot of territory.
"And as I said you don't get a lot of opportunities at this level, so you've got to be disciplined and you've got to be accurate, and we were neither tonight."