Fast bowler Dale Steyn missed training on Monday after feeling tightness in his right hamstring while practising on Sunday afternoon.
A Cricket South Africa statement said the Proteas’ medical team were assessing the extent of the injury.
Meanwhile, the world’s top batsman Hashim Amla, who scored a century in the first test which the world number one side lost by seven wickets, is awaiting the birth of his second child in Durban. If Amla is to play he will need to leave for Dubai around midday on Tuesday.
Pakistan’s victory ended a run of 15 matches without a loss for the Proteas, who had not played in the test arena for 10 months.
“It is important to find a solution,” said vice-captain AB de Villiers.
“We are the number one ranked team in the world and we are going to have to go out there and play like that.
“Technical changes can’t happen, we have to believe and have a fresh mindset that we are going to level the series.”
South Africa failed to pass 250 in either innings at the Sheikh Zayed Stadium and new coach Russell Domingo called it “a soft performance from the batting unit”.
Pakistan coach Dav Whatmore said he was not surprised by the win despite an upset loss to Zimbabwe last month.
“I knew that we could be competitive in different conditions and with a slight change of personnel. We gave a good competitive effort over the four days,” Whatmore told reporters.