Proteas' three pacemen all nursing niggles

South Africa could be reduced to one fit bowler in the final innings of the fourth Test, with Kagiso Rabada, Vernon Philander and Morne Morkel all nursing injuries of varying severity.

Morkel suffered a side strain and trudged off the field on day three in Johannesburg, where he was unable to continue bowling.

The Proteas say Rabada (sore back) and Philander (groin) will also need to be carefully managed throughout the rest of the match.