The Wallabies will be without vice-captain Michael Hooper for its final pool game, after the flanker pleaded guilty to a Foul Play charge on Tuesday.
Hooper was cited for a 39th minute clean out on England fullback Mike Brown, under Law 10.4, which relates to charging into a ruck or maul without using arms.
The flanker was penalized at the time but not yellow carded for the incident.
The judicial officer deemed the offence was on the lower-end, with a maximum two-week suspension but Hooper’s early admission and good behavioural record reduced that penalty to just the one week.
Hooper will be available for the Wallabies quarter-final, against any one of South Africa, Scotland or Japan depending on the results of this weekend’s games.