Wales are likely to field an unfamiliar back row against Australia in Cardiff on Saturday with Justin Tipuric yet to train since suffering a thigh injury last month.

With the Lions’ captain, Sam Warburton, out until the new year and the player who stood in at openside against Samoa in the summer, Ellis Jenkins, also injured, Wales’s options if Tipuric fails to make the training field by Thursday morning are Josh Navidi, Aaron Shingler and Sam Cross, who have 13 caps between them.

The scrum-half Rhys Webb, a summer Lion along with Tipuric, is also a doubt having sat out training since suffering a knee injury playing for Ospreys against Clermont Auvergne last month.

“The team is named on Thursday and we will wait until the last minute,” said the Wales defence coach, Shaun Edwards. “They will both have to take part in training to put up their hands for selection. They both played very well on the Lions tour but, if one man goes down, another will come in equally determined and openside wing forward is a position of strength in Wales.”

It is nine years since Wales beat Australia, their group opponents again in the 2019 World Cup. While most of their 12 successive defeats have been by single-figure margins, an exception was last year when the Wallabies won 32-8 at the Principality Stadium.

“Australia pose an unbelievable attacking threat and are averaging 33 points a game,” Edwards said. “The World Cup adds a bit of spice to it but ever since Warren Gatland has been the head coach here we have always had tough matches in the autumn and are again playing Australia, New Zealand and South Africa: he is not one to take the easy option.

“I would say Australia are the most potent attacking force in world rugby over the first three phases, more than the All Blacks. We were average against them last time and aim to do better on Saturday. We have traditionally been slow-starters: last year we had only one training session before we faced Australia but we have had everyone together for more than a week.”

Last season Edwards said it was the most challenging period he had faced as a defence coach in rugby union with the ball-in-play time increasing, and tweaks to the way the breakdown was controlled favouring the attacking side and teams rarely managing to keep their line intact.

“It is even more so now,” he said on Monday. “You only have to look at statistics and the number of tries that are being scored. If you can keep an opponent to around 25 points in good conditions – rain does affect the attacking prowess of teams but we have the roof in Cardiff to keep it out – you give yourself a chance.

“Our backs are quite a lot smaller than they used to be and against a pretty huge Australian back division our line speed is going to have to be top-drawer to cut down their time on the ball. We have worked hard on it in the last seven days and the change in our attacking game has put extra pressure on me. Defence, though, will always be important.”