Drew Mitchell has become the latest Europe-based Wallaby to return overseas, not included in the Wallabies squad for the upcoming tour of South Africa and England.

Mitchell has been released from the 30-man squad for the final two Rugby Championship matches against South Africa and Argentina, to return to Toulon and gain some match fitness.

The 32-year-old has featured just once for the Wallabies in 2016, coming off the bench in the Wallabies’ Brisbane clash against South Africa, after struggling with a groin injury that kept him out of the final stages of the European season.

Rebels flyer Sefa Naivalu is one step closer to reaching his Wallabies dream, included in the travelling group after becoming eligible for Tests on September 18.

Hooker Tolu Latu is a surprise inclusion in the squad, his first chance at a Wallabies berth under Michael Cheika, after some promising form in the NRC.

Latu comes in for Tatafu Polota-Nau, who has been managing an arm injury for much of the season, and has been rested.

Wallabies coach Michael Cheika said he was giving the backup hooker time to look after his fitness, after battling the niggle all year.

“It is disappointing for Tatafu, who has been one of the most consistent and valued members of our finishers off the bench, he needs time to get his body right and we respect that," he said.

“We're happy with how Drew and Ben are progressing. The best thing for both players is to play some regular rugby to get themselves back to full form and fitness.

“With injury comes opportunity, and this is the opportunity now for Tolu to make his step up to International rugby.

"All our newly capped players this season have taken their chances with both hands and I expect Tolu to do the same, which should give all our fans confidence in the future.”

Ben McCalman will also remain at home, after overcoming a broken scapula, with the number eight left to gain some more game time in the NRC with the Perth Spirit, for whom he debuted last weekend.

That leaves Lopeti Timani and Sean McMahon as the main candidates to replace injured backrower David Pocock, who broke his hand against Argentina.

Injured prop Allan Alaalatoa looks a chance to be included in one of the two Tests, returning to the squad after a medial ligament injury suffered in Brisbane.

The 22-year-old missed the Argentina Test and looked doubtful for Pretoria, but will be heading to South Africa on Saturday, along with his Perth replacement, rookie Tom Robertson.

Will Genia is the last European Wallaby standing ahead of the three-week trip and the halfback has been one of the Wallabies' best in the Rugby Championship, after a seven-month layoff.

Reds halfback Nick Frisby has been added to the halfback stocks, looking to add to his two-Test tally, after being left out of the official Rugby Championship squads with Genia’s return.

Kyle Godwin, Will Skelton and Toby Smith have also dropped out of the squad that assembled in Perth last week.

The Wallabies head to South Africa on Saturday morning, ahead of their Pretoria Test at 1:05am AEST Sunday October 2.

Wallabies Rugby Championship squad

Ins: Nick Frisby, Tolu Latu

Outs: David Pocock, Kyle Godwin, Tatafu Polota-Nau, Will Skelton, Toby Smith, Drew Mitchell

Full 30-man squad

Allan Alaalatoa (Brumbies), Rory Arnold (Brumbies), Adam Coleman (Force), Quade Cooper (Reds), Kane Douglas (Reds), Scott Fardy (Brumbies), Israel Folau (Waratahs), Bernard Foley (Waratahs), Nick Frisby (Reds), Will Genia (Stade Francais), James Hanson (Rebels), Dane Haylett-Petty (Force), Reece Hodge (Rebels), Michael Hooper (Waratahs), Sekope Kepu (Waratahs), Samu Kerevi (Reds), Tevita Kuridrani (Brumbies), Tolu Latu (Waratahs)*, Sean McMahon (Rebels), Stephen Moore © (Brumbies), Luke Morahan (Force), Dean Mumm (Waratahs), Sefanaia Naivalu (Rebels)*, Nick Phipps (Waratahs), Tom Robertson (Waratahs), Rob Simmons (Reds), Scott Sio (Brumbies), James Slipper (Reds), Henry Speight (Brumbies), Lopeti Timani (Rebels)

*Uncapped