A complicating factor for Starc and Green is the ICC regulations that do not permit bowlers to wear any tape or strapping on their bowling hand which means they are unlikely to be able to protect their injuries.

Captain Pat Cummins and Scott Boland are the other two frontline quicks while Nathan Lyon can expect a big workload if resources are stretched. Travis Head's offspin, which has picked up handy wickets this year, and Marnus Labuschagne's combination of legspin and medium pace could also be called on. Australia secured victory against West Indies in Perth earlier this season without Cummins in the second innings when he suffered a quad injury.

It was a busy day for the medics in sweltering conditions that touched 40 degrees in Melbourne. Warner started to suffer cramps in the 56th over when he was in the 120s and they returned in a more severe manner as he neared his double century in the final session.

After lengthy treatment on the outfield he brought up the milestone but after barely being able to celebrate he could not resume and was helped off the field. However, after rehydrating in the dressing room the signs were positive for him after play.

The extreme heat is expected to dissipate overnight with a top of 28 degrees forecast for Wednesday and the potential of some showers interrupting play. The final two days are set to be dry.

At the close of the second day Australia held a lead of 197 having flayed South Africa's attack in a last session that brought 155 runs from 28 overs. Only 79 of the day's allocation of 90 overs were completed due to various stoppages, largely caused by the heat, which saw an extra drinks break taken as well the treatments for cramp.