James O'Connor will practice with the Wallabies ahead of their Rugby Championship opener against South Africa, although he is yet to sign with an Australian club on his return from England.
The 44-Test veteran was due to fly out Monday to join the Australian squad in South Africa as they prepare for the match against the Springboks on July 21, live on Sky Sports.
Rugby Australia said the 29-year-old utility back would join the squad on a "train-only" basis.
O'Connor was called on after winger Marika Koroibete was allowed to remain in Australia, awaiting the birth of his second child.
Sale Sharks released O'Connor from his three-year contract so he could return to Australia and fight for a place in their World Cup squad.
He won the last of his 44 Wallabies caps in 2013, and having signed a contract with Rugby Australia, will reportedly play for the Reds in Super Rugby next season.
His international career was hampered by off-field controversies, including an arrest in Perth in 2013 which briefly cost him his Australian contract.
O'Connor stayed out of trouble since joining Sale in 2017 and the sacking of full-back Israel Folau has left Australia head coach Michael Cheika with a vacancy in his Wallabies backline.
Chieka said Koroibete "should join us later in the week but mother nature is in charge here, so until then it's a good opportunity for James to integrate into the team playing principles".
Meanwhile, backrower David Pocock will continue his recovery from a calf muscle injury with the squad in South Africa.
"For David, we really want to do some specific rehab work and it's just better to have him with us at this stage to ensure we get his return to play exactly right," Cheika added.