BRISBANE, AUSTRALIA - NOVEMBER 22: David Warner stretches during an Australian nets session at The Gabba on November 22, 2017 in Brisbane, Australia. (Photo by Chris Hyde/Getty Images)

David Warner and Steve Smith played vital roles in the reason as to how Australia reclaimed the Ashes just a month ago.

However, question marks have been raised about their own personal schedules, with Warner playing every test, ODI and T20, while Smith just sat out the T20 series.

Warner's white ball form this summer has been horrendous, averaging just 10 runs per innings in both the ODI and T20 formats.

Leading cricket analyst, Robert Craddock has signalled that Warner's loss of form is a major worry heading to South Africa.

"“You can just see he is exhausted,” he told SEN's Whateley, continuing on to explain his form is not what it was at the beginning of the series.

"I know he spent a couple of hours in the nets with Ricky Ponting the other day."

"I felt his dismissal [Saturday Night], just a left footed edge."

The impact that not only the summer has had on Warner and Smith in particular been extravagant, the impact of the IPL also contributes, with both leading their respective franchises.

In the case that Warner doesn't improve on his form, it would spell complete disarray for the Australians, with Bancroft also struggling at the top of the order.

With the squad set to jet off later this week, Craddock has also argued the selection of Billy Stanlake, who's played two Sheffield Shield games in his career, over the likes of Chadd Sayers to replace Jackson Bird, who is likely to be omitted.

“Billy hasn’t done the work,” he said. “He would deliver the most potent new ball spell of any of them, but he has played two Sheffield Shield games in his career, the last one a couple of years ago.