Out of form: Recovering from the head knock Kurtley Beale sustained against Georgia is just one of his challenges. Credit:Getty Images England left winger Jonny May is a handful – probably the fastest in their squad – and that must play into considerations as well. However, my faith in Petaia isn’t about to waver now. I’d stick with the youngster with Ashley-Cooper’s versatility and experience on the bench. 2. Wallabies scrum must be respected by referees Wallabies coach Michael Cheika must walk a tricky line this week.

How can he convey his obvious frustration that the Wallabies’ scrum is being refereed hard without sounding like he is trying to pressure the referee for the quarter-final? He won’t be the first Wallabies coach to wrestle with the conundrum but he is unique in the sense that he is the first coach in a while to have some genuine scrummaging power in his front-rowers. When he talks up the Wallabies’ scrum, it’s not just hot air. Laying down the law: Michael Cheika oversees a scrum session in Tokyo. Credit:Rugby AU Media/Stuart Walmsley The key match-up in Oita is clearly going to be Scott Sio against Kyle Sinckler. The Englishman is an explosive, destructive tighthead and if the scrum penalties are going to go one way or the other you suspect it will be on Sio’s loosehead side. For the sake of the Wallabies, you just hope that the game is officiated without preconceptions at the scrum. It was at this stage in the 2015 Rugby World Cup that Sio started to get pinged and perceptions of the Wallabies having a ‘weaker’ scrum can be hard to shake.

3. Australian referee Nic Berry’s star is on the rise The referees can’t win at this tournament – either they implement World Rugby’s rules around the high tackle, which fans largely don’t like, or they won’t get the plum games at the business end of the competition. Setting aside the ‘game’s gone soft’ debate, Berry’s control of the flashpoint incidents in the Samoa v Ireland game was very good. Impressive: Nic Berry controlled the flashpoints in the Ireland-Samoa match with a level head. Credit:Getty Images He was very clear and articulate in his communication of his thought process, and although he asked his assistants for their opinion it was clear that Berry had taken control of the situation and had a firm opinion of where Bundee Aki and Seilala Lam’s tackles sat on the decision-making framework for high tackles.

Tall timber: Rory Arnold's contact work is an issue. Credit:Getty Images I’m yet to hear a former player say that Lam’s tackle was anything but a rugby collision, but Berry is refereeing the game the way World Rugby wants to it be and he might be in line for a big assignment in coming weeks. 4. The area of concern in the Wallabies pack While the Wallabies’ set-piece has done the job, we are seeing why the Wallabies were throwing out a few fishing lines to Will Skelton. Izack Rodda is as honest as the day is long – he’ll put his hand up for the tough carries. However, Rory Arnold still has a tendency to go into contact a little bit high and they will be exploited by the likes of England’s George Kruis and Maro Itoje.

To be fair to Arnold, it’s not easy to go low when you are so tall but the high expectations Wallabies fans had of his presence at this Rugby World Cup probably haven’t quite materialised in terms of his ball carrying. Adam Coleman is a similar athlete and it’s Skelton’s point of difference that makes him appealing – no doubt his Saracens mates Itoje and Kruis are quite glad he won’t be there on Saturday. The Wallabies can’t waste time thinking about absent friends – they have managed to repatriate a fair number of overseas-based stars – but Skelton and Sean McMahon definitely had something to offer. 5. The Waratahs youngster to make his mark It could easily slip under the radar but the Waratahs’ heavy investment in youth, as revealed by colleague Georgina Robinson, is both exciting and a sign of the times.

Loading Super Rugby is getting younger, partly by player market forces rather than choice, and the Waratahs have signed up an astonishing 12 players from this year’s Junior Wallabies. That influx of fresh blood brings a feelgood factor but this group will encounter some bumps over the next few years. Queensland are probably a bit further down the track with a similar plan, and the long-term signing of excitement machine Isaac Lucas is the last piece of their puzzle. New Waratahs such as Angus Bell and Will Harrison are going to need time to develop, due to the positions they play (prop or No.10, respectively), but there is one player who could make an immediate impact next year. Winger Mark Nawaqanitawase is an excellent athlete and outside backs can obviously prosper a little bit quicker than young forwards or inside backs.