Steyn missed the second test, which ended in a draw in Cape Town on Wednesday, after suffering a shoulder spasm during the first test in Durban, where he bowled only 22 balls in the second innings.
While a scan in Durban showed no muscle damage, Steyn is seeking a second opinion from another specialist ahead of a fitness test when the squad meets up again in Johannesburg on Monday.
Steyn suffered a groin strain in November and missed three of the four tests in India and his latest injury has been blamed on a heavy bowling workload so soon after the layoff.
Philander has been sidelined since suffering ankle ligament damage in India during a warm-up football drill.
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Kyle Abbott, who also missed the second test with a hamstring strain, has been declared fit for the next encounter against England.
The third test will take place at the Wanderers from Jan. 14-18.
(Editing by Pritha Sarkar)
