Australia and South Africa will get their three-Test series underway at the Gabba on Saturday, with the number one and two ranked sides in the world playing for pivotal points in the World Test Championship.

Not only that, but the rivalry between the two sides has reached fever pitch in recent years following the controversial 2018 ball tampering scandal.

South Africa have won their last three series down under, but will bring a different-looking side to this year's challenge, while Australia are facing their own questions.

Here are the five players who could decide the series.

Dean Elgar

The South African veteran and captain is vastly experienced and has batted against Australia on 19 occasions.

PERTH, AUSTRALIA - NOVEMBER 05: Dean Elgar of South Africa bats during day three of the First Test match between Australia and South Africa at the WACA on November 5, 2016 in Perth, Australia. (Photo by Paul Kane/Getty Images)

His efforts against Cricket Australia XI were solid, top scoring with 109 from 186 and 26 from 78. He has scored a century twice against Australia and has scored three half-centuries.

However, his batting average is the second worst against Australia with a 33.55 average. Only against Pakistan does he have a worse average (25.84).

His worst strike rate is against Australia with a 38.59, with his figures even lower when playing Tests in Australia. Elgar has an average of just 23 runs with a strike rate of 37.01. The key is not only his leadership skills for his side but setting the tone with the bat.

Going at a slower strike rate is not a problem if he is there for the long run although he is yet to really do that in Australian conditions. Other international players who have succeeded that way include Cheteshwar Pujara of India who has an average of over 47 runs in Australia playing this very way.

So, the key for Elgar is maintaining that form from the warm-up game, keeping a steady pace and not throwing his wicket away cheaply by edging a shot he doesn't need to play.

3. Scott Boland

The three names up for Josh Hazlewood's place were Scott Boland, Michael Neser and Lance Morris. Losing someone with the quality of Josh Hazlewood, means finding a replacement is difficult. With the shoes to fill even more difficult.

Australia v England - 3rd Test: Day 3
MELBOURNE, AUSTRALIA - DECEMBER 28: Scott Boland of Australia appeals successfully for LBW to dismiss Jonny Bairstow of England during day three of the Third Test match in the Ashes series between Australia and England at Melbourne Cricket Ground on December 28, 2021 in Melbourne, Australia. (Photo by Robert Cianflone/Getty Images)

With Mitchell Starc just coming off playing two Tests and Pat Cummins overcoming a slight injury, Boland's job could be even harder.

Good news for Australian fans is all the replacement options are all very capable of filling the biggest of shoes. Boland and Michael Neser have shown their quality as replacements, with Boland recording a 10.33 average at an economy of 2.02 so far in his test career, while Neser has recorded an average of 16.71 with an economy of 2.49.

Lance Morris is uncapped and was always unlikely to get called up over Boland and Neser, but he has great pace hitting over 150 kilometres per hour and is currently topping the Sheffield Shield for wickets.

Scott Boland seems to be the most capable candidate to be the main replacement, and he will look again to justify his selection with his consistency and accurate economical bowling.