Cape Town - The Proteas will slip to No 4 in the official ICC Test rankings if they lose their current home series 3-0 to England.
Following their seven wicket win at the Wanderers last week, England boast an unassailable 2-0 series lead heading into Friday’s final Test in Centurion.
The result also ensured that South Africa cannot finish the season as the No 1-ranked Test team in the ICC Test Championship.
The team on top of the standings at the April 1 cut-off date wins the ICC Test Championship mace - -and $1m (R16.5m).
When the ICC Test Championship table is updated following the conclusion of the Centurion Test, to be played from January 22-26, India will replace South Africa as the No 1-ranked Test side.
The best Test ranking South Africa can now achieve is second position, which will only be possible if they win the Centurion Test.
If the Test ends in a draw, then South Africa will drop to third position behind India and Australia, while a 3-0 series loss will result in the Proteas finishing in fourth place behind India, Australia and Pakistan.
In contrast, England will finish above New Zealand in fifth place irrespective of how the Centurion Test pans out.
This situation will be of tremendous interest to Australia, who now have an excellent chance to finish as the No 1-ranked Test side at the April 1 cut-off date.
In the final Test series before action shifts to the ICC World Twenty20 India, Australia travel to New Zealand for a two-Test series, and if they win the series, then they will win the ICC Test Championship mace.