That still might not happen though given Toomua has been one of Australia’s most consistent performers in the last three Tests of the Rugby Championship.
He and Beale combined well together against the Springboks but is understood Cheika now feels Beale’s creativity and desire to attack the line would be better suited at inside-centre.
Both Toomua and Foley ran at No.10 at training on Tuesday at the San Isidro Club in front of a handful of avid Argentinian onlookers.
Beale shifting to No.12 almost certainly means either Foley or Toomua will be on a bench that may well feature a specialist back-row replacement this time around.
Cheika’s decision to use Rob Simmons, a renowned second-rower, as back row cover certainly raised a few eyebrows from armchair selectors. Someone like an Angus Cottrell could make his Test debut off the pine, or the Wallabies could opt for someone like Caleb Timu, who was used twice during the June series against Ireland.
The Wallabies won’t name their team until Thursday local time but there is not expected to be wholesale changes across the starting XV despite a mountain of pressure on the squad to produce a win in Salta.
The team did not do a field session on Monday because of the travel from South Africa, meaning Cheika has one less session to get a gauge of who has pulled up favourably from the 23-12 loss to South Africa in Port Elizabeth.
Even though Australia’s lineout was shaky once again on the weekend, Folau Faingaa has trained well and is a good chance of retaining his spot.
As for Jack Maddocks’ replacement, Tom Banks looks most likely to earn a spot on the bench.
There is, however, a chance he could start if Marika Koroibete does not pass his return to play protocols as a result of a concussion but the Wallabies are confident he will be right after getting through training. A final call on Koroibete, who set up a Will Genia try on Saturday, won’t be made until later in the week.
Whatever side the Wallabies pick, they will need to give a better account of themselves after being humiliated in front of home fans just under three weeks ago.
Former Wallabies assistant turned Pumas coach Mario Ledesma will have his men firing to inflict back-to-back wins over Australia for the first time since 1979 when the teams had their maiden international outing against one another.
Argentina have already set up base in Salta and have the advantage of getting used to the thinner air of the town nearly 1200 metres above sea level. It will be Australia’s first game in Salta but not Cheika’s, who coached a NSW touring team there in 2013.
The Wallabies travel to Salta on Thursday afternoon ahead of the match at Estadio Padre Ernesto Martearena.
Tom Decent is a journalist with Fairfax Media.