But Warren Gatland decided against it and now seems set to ask either Jonathan Thomas or Dafydd Jones, both natural blind-side flankers, to play out of position against the likes of Schalk Burger.
The Wales squad has been ravaged by injuries, with Williams joined on the sidelines this summer by fellow Grand Slam winners Gavin Henson, Lee Byrne, Dwayne Peel and Mike Phillips.
The scrum-half role will be contested by Gloucester's Gareth Cooper, third choice during the RBS 6 Nations, Andy Williams and the uncapped London Irish half-back Warren Fury.
Cardiff second-row Bradley Delve and Ospreys full-back Andrew Bishop are the other uncapped players to be included in the 27-man squad.
Jones, the Llanelli blind-side flanker, is in line to win his first Test cap since 2006 after a string of injuries kept him out of the international scene.
Despite the injuries, the bulk of Gatland's squad boast Grand Slam-winners medals and the tight-five looks competitive with the likes of Duncan Jones, Adam Jones, Gethin Jenkins, Huw Bennett, Ian Gough, Alun-Wyn Jones and Ian Evans all travelling.
In the backs, Gatland has experienced heads like James Hook, Stephen Jones, Sonny Parker Tom Shanklin, Shane Williams and Mark Jones.
The concern is inexperience in key positions, not only on the openside flank but at full-back where contenders Morgan Stoddart and Jamie Roberts have just one cap each.
The first Test is in Bloemfontein on June 7 with the second a week later at Loftus Versfeld in Pretoria.
Wales squad for Test matches against South Africa in Bloemfontein on June 7 and Pretoria on June 14:
Backs: M Stoddart (Llanelli Scarlets), A Bishop (Ospreys), J Roberts (Cardiff Blues), S Williams (Ospreys), T James (Cardiff Blues), M Jones (Llanelli Scarlets), S Parker (Ospreys), T Shanklin (Cardiff Blues), S Jones (Llanelli Scarlets), J Hook (Ospreys), A Williams (Newport Gwent Dragons), W Fury (London Irish), G Cooper (Gloucester).
Forwards: Duncan Jones (Ospreys), G Jenkins (Cardiff Blues), A Jones (Ospreys), R Thomas (Newport Gwent Dragons), M Rees (Llanelli Scarlets), H Bennett (Ospreys), I Gough (Ospreys), A-W Jones (Ospreys), I Evans (Ospreys), B Davies (Cardiff Blues), J Thomas (Ospreys), Dafydd Jones (Llanelli Scarlets), G Delve (Gloucester), R Jones (Ospreys, capt).