De Villiers abruptly retired from the international arena after suffering a broken jaw against Samoa last week.
Several senior players who could take over are injured - which has dashed coach Heyneke Meyer's hopes of naming his new leader before Wednesday's team announcement.
Vice-captain Victor Matfield is struggling with a hamstring strain and scrumhalf Fourie du Preez (ribs) is also in doubt.
These and a number of other injuries forced the cancellation of Monday's training and the delay in the team announcement until late Wednesday.
Other candidates include Duane Vermeulen, who only returned from a neck injury in the 46-6 rout of Samoa at Villa Park last week.
Flank Francois Louw, hooker Adriaan Strauss and loose forward Schalk Burger, who captained the Boks against the All Blacks this year, could also get the nod.
There was little indication at Tuesday's practice session as to who will take the leadership.
However, South Africa must be certain to avoid a repeat of their shock loss to japan when they take on the Scots at Newcastle United's St James Park.
Meyer also faces a few interesting selection posers, with De Villiers' replacement Jan Serfontein poised for a dramatic recall.
Serfontein missed out on the World Cup squad because of the emergence of midfielders Damian de Allende and Jesse Kriel.
The duo, if fit, are likely to start against Scotland.
However, De Allende has a knee ligament strain and Kriel a nasty gash to the cheek after taking a boot in the face in the Samoa win.
Serfontein, who played all 12 Tests for the Boks in 2014, struggled with a hip flexor injury this year, which hampered his chances of making it to the World Cup.
The Springboks are also expected to bring back fiery hooker Bismarck du Plessis to the match day squad.
Agence France-Presse
