The Wallabies selection of just two specialist hookers in the squad has come under fire from some quarters but the side remains confident they are on the right track.
Stephen Moore and Tatafu Polota-Nau will likely be backed up by prop Scott Sio if any problems arise.
"The work we have done, not only the last week or two but also over the Rugby Championship with Mario [Ledesma] our new scrum coach and the fact the players in the squad have all bought into the philosophy we want to take into games, has us confident," Slipper added.
"The game against the US was a step forward but we know in our heads that we are going to have to keep improving because it will be a major focus at the World Cup."
Niko Matawalu's two-try cameo has fired England and other cup teams a warning as Fiji dispatched Canada 47-18 in a warm-up at The Stoop in Twickenham.
The halfback bossed Fiji's fluent, potent backline under the shadows of Twickenham yesterday, 13 days before the Pacific Islanders will look to spoil England's World Cup party.
Matawalu limped off gingerly just before halftime with a leg injury, but was clearly removed as a precaution and under little panic.
The 26-year-old's class is underscored by his ability to stand out as Fiji's biggest threat even in a backline dripping with strike runners and match-winners.
- AAP