Arguably the world’s best batsman – he is ranked third in Tests and first in one-day internationals – De Villiers, 31, made no secret of his ambition to captain the South African Test team following the retirement of Graeme Smith in 2014.
But Cricket South Africa decided to appoint Hashim Amla instead, with De Villiers continuing to lead the one-day side.
Now De Villiers has the job he wanted, following the surprise resignation of Amla after the second Test last week — but only for the remaining two matches of the series.
A long-term appointment will probably not be made for some time, with South Africa not due to play another Test series until they meet New Zealand in August.
De Villiers takes over at a difficult time. Despite fighting back strongly to draw the second Test in Cape Town, South Africa have gone eight Test matches and more than a year without a win.
England lead the series 1-0 and South Africa will lose their number one Test ranking unless they can earn at least a share of the series honours.
The Wanderers has traditionally favoured fast bowlers, but the bowling firepower at De Villiers’ disposal has been severely depleted by injuries to Dale Steyn and Vernon Philander.
As was the case in the second Test, it leaves Morne Morkel as the only experienced bowler in the line-up.
The bowlers took some severe punishment at the hands of Ben Stokes and Jonny Bairstow at Newlands, although they performed better in the second innings.
Picking the right bowling line-up will be a key factor for South Africa, with Kyle Abbott and the uncapped Hardus Viljoen, who plays for the Wanderers-based Lions franchise, coming under consideration.
There is also a possibility that South Africa might decide to go without specialist spin bowler Dane Piedt, which could mean a recall for batsman and part-time spinner JP Duminy.
England have no selection dilemmas following strong performances in both Test matches so far.
The only player in their side who has not made at least one significant contribution is captain Alastair Cook, who has made just 42 runs in four innings.
South Africa (likely): AB de Villiers (captain), Dean Elgar, Stiaan van Zyl, Hashim Amla, Faf du Plessis, Temba Bavuma, Quinton de Kock (wkt), Morne Morkel, Kagiso Rabada, Dane Piedt or JP Duminy, Chris Morris or Kyle Abbott or Hardus Viljoen.
England (likely): Alastair Cook (captain), Alex Hales, Nick Compton, Joe Root, James Taylor, Ben Stokes, Jonny Bairstow (wkt), Moeen Ali, Stuart Broad, Steven Finn, James Anderson.
Umpires: Kumar Dharmasena (SRI), Chris Gaffaney (NZL)
TV umpire: Rod Tucker (AUS)
Match referee: Ranjan Madugalle (SRI)