James O'Connor flies to join Wallabies

Former bad boy James O'Connor is flying out to link with the Wallabies squad in South Africa even before signing to return to Australian rugby.

O'Connor got the chance after winger Marika Koroibete was allowed to remain in Melbourne for the imminent birth of his second child.

Rugby Australia says O'Connor, who wants to return ahead of this year's World Cup, will join the squad on a train-on basis only.

It's understood 29-year-old O'Connor's contract talks with the Queensland Reds are progressing well and a deal is likely before the opening Rugby Championship Test against the Springboks in Johannesburg on Saturday week.

The 44-Test utility back will be joined on the flight by injured backrow star David Pocock, who is to continue rehab on his problematic calf muscle while in South Africa.

Wallabies coach Michael Cheika expects Koroibete to rejoin the squad well before the Springbok Test but meanwhile RA were able to switch his flight booking over to O'Connor.

"Marika (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," said Cheika.

"For David, we really want to do some specific rehab work with him and it's just better to have him with us at this stage to ensure we get his return to play exactly right," Cheika said.

While his previous career in Australia was marked by several off-field indiscretions, the gifted O'Connor received praise from his latest employers, English club Sale, for his contribution there last season.