Justin Tipuric and Rhys Webb are major doubts for Wales’ autumn series opener against Australia on Saturday.

Flanker Tipuric has a thigh injury while scrum-half Webb is nursing a knee problem ahead of a demanding schedule that also sees Wales tackle Georgia, New Zealand and South Africa.

Wales are already without injured openside Sam Warburton – the British and Irish Lions captain will not play again until later this season – so 51 times-capped Tipuric’s absence would prove a considerable blow.

Cardiff Blues forward Josh Navidi, who has won three caps, could now make the back-row trio, potentially lining up alongside Aaron Shingler and Taulupe Faletau.

And if Ospreys No 9 Webb is ruled out, then the Scarlets’ Gareth Davies can expect a start as Wales look to end a run of 12 successive defeats against Australia.

“Justin Tipuric is carrying a bit of a knock and so is Rhys Webb, so we will just wait until the last minute,” said Wales assistant coach Shaun Edwards. “The team is named on Thursday.

“They will have to (take part in training) to put their hands up for selection. Both were on the Lions tour recently and both played very well on that tour.”

Wales head coach Warren Gatland, meanwhile, is expected to name Gloucester back Owen Williams at inside centre, with Scarlets wing Steff Evans taking over from an injured George North.

Edwards is braced for a stern test against the Wallabies, who have arrived in Wales fresh from beating world champions New Zealand and then crushing 2019 World Cup host nation Japan.

“We all know what an unbelievable attacking threat Australia are, averaging 33 points a game,” Edwards added.

“If you look at our fixtures since Warren took over, they have always been tough in the autumn.

“We nearly always play the likes of Australia, South Africa and New Zealand, and we are playing all three this time. It is certainly not a resting month, put it that way.

“Australia are an immense attacking weapon. I would say they are the most potent attacking force in the first three phases in world rugby, probably even more than the All Blacks.

“They are perennially a top-four ranked team, their attack is pretty prolific and they have a multitude of excellent backs.”