Number 15 ... Mike Harris is likely to be the Australian fullback for this weekend's Test against Argentina.

Number 15 ... Mike Harris is likely to be the Australian fullback for this weekend's Test against Argentina. Photo: Getty Images

Rosario: Mike Harris is set to become the fifth Wallabies fullback in ten Tests this season and Dave Dennis is under threat of being replaced in the backrow for Saturday night's international against Argentina.

In the team's first training run since arriving in Argentina from South Africa, Harris, better known as a five-eighth or centre for the Queensland Reds, ran at fullback. This position became vacant after Berrick Barnes punctured his lung during last weekend's 31-8 loss to the Springboks in Pretoria.

There is uncertainty over whether Anthony Faingaa or Ben Tapuai will take over at No 13 after Adam Ashley-Cooper was forced to return home after being badly concussed against the Springboks. Both Faingaa and Tapuai had time training in the centres during the two-hour session, which was held at the plush Rosario Jockey Club grounds.

Digby Ioane and Scott Higginbotham sat out the session due to injury, but Wallabies officials are hopeful they will be available for Australia's final Rugby Championship match.

Sitaleki Timani is a strong possibility of starting at No 6 ahead of Dennis, while James Slipper may be promoted over Benn Robinson as the loosehead prop. Nick Cummins ran in Ioane's wing spot.