Cape Town - Australia coach Michael Cheika is confident that centre Tevita Kuridrani will be fit for Australia's World Cup opener against Fiji, but rookie utility back Jordan Petaia’s is still a major doubt.

Kuridrani and Petaia trained separately to the main group on Wednesday, both working their way back from hamstring injuries.

Petaia went back to Australia early from the Wallabies’ pre-tournament camp in Noumea while Kuridrani tweaked his hamstring in the build-up to last weekend’s Samoa Test.

Cheika said Kuridrani would likely be back in the mix for Australia’s September 21 opener against FIji, but Petaia could remain out of action until as late as the Wallabies’ October 5 Test against Uruguay in Oita.

"Tevita, he's running nearly back at full pace so I'm hopeful he’s going to be right to be available for selection next weekend," Cheika told Rugby Australia’s official website.

"Our target for Jordan is a couple of weeks later, but he’s on track.

"If not Wales, the one after but we’re hopeful it’ll be for Wales. If not, I’m comfortable with the one after."

With that pair still not match fit, the Wallabies couldn’t really afford another injury in the backline, and certainly the roles of utilities James O’Connor and Adam Ashley-Cooper could become more critical if there was another injury setback.

Lock Adam Coleman also worked separately for much of the main training session on Wednesday in Odawara, still nursing a hand injury from last weekend’s match against Samoa, but Cheika played down any concerns about the second rower.

Rebels forward Luke Jones was flown to Japan to join the squad at the last minute with Coleman being wrapped in cotton wool, arriving on Tuesday morning.