Springbok scrum-half speedster Williams gets chance to impress
Speedster Williams can also operate as a winger -- a plus as head coach Rassie Erasmus favours those who can operate in more than one position.
There are five scrum-halves seeking to top the pecking order, including two-time World Cup winner Faf de Klerk.
De Klerk was omitted for an end-of-season tour to Europe last year, but the 33-year-old came off the bench in an unimpressive 42-24 win over Italy in Pretoria last Saturday.
Cobus Reinach, who will be on the bench in eastern coastal city Gqeberha, Jaden Hendricks and new kid on the block Morne van den Berg are the other challengers.
Van den Berg scored two tries and was one of the few Springboks to emerge from the victory over the Azzurri in Pretoria last Saturday with his reputation intact.
But he will miss the second and final Test against Italy because Erasmus wants to rotate his matchday 23 to assess all those in his 45-man squad.
After the series against Italy, only two forwards, uncapped prop Boan Venter and regular captain and flanker Siya Kolisi, will not have worn the green and gold after three matches this season.
Glasgow-based Venter is likely to win his first cap against Georgia on July 19 in Mbombela while a stiff neck, then an Achilles tendon "niggle" have kept Kolisi sidelined.
"It was a tough decision to rest Kolisi, but I feel the wise decision was to rest him for another week," Erasmus told reporters.
"It is not a serious injury, but you know how an Achilles tendon is, if you rest it another week it can only be better for the player. Hopefully he will play next week."
'Fantastic playmaker' Le Roux
Veteran full-back Willie le Roux is poised to become only the eighth Springbok to be capped 100 times -- 12 years after making his debut in Durban against Italy.
"Willie has been a stalwart for us in the past few years and a fantastic playmaker. We are thrilled to see him achieve this incredible feat," said Erasmus.
"I have no doubt he will put the team before his own achievement, and the team would certainly like to make it a special and memorable occasion for him."
Le Roux, 35, is among 11 changes to the Pretoria starting line-up and the bench includes three uncapped players -- wing/centre Ethan Hooker, prop Asenathi Ntlabakanye and lock/flanker Cobus Wiese.
"Italy are a brave and tough team and we know that their performance last week will psyche them up going into the second Test," said Erasmus.
"They will come hard at us and deliver another passionate performance. We need to shift into a different gear (after) an honest and thorough review of what happened last weekend."
Italy coach and former Argentina fly-half Gonzalo Quesada has made four personnel changes and one positional as they seek a first victory in South Africa over the record four-time World Cup winners.
Mirko Belloni wins a first cap at full-back, replacing Jacopo Trulla, who moves to the left wing with Simone Gesi dropping out.
Alessandro Garbisi takes over from Alessandro Fusco at scrum-half, South Africa-born number 8 Ross Vintcent replaces injured Lorenzo Cannone and flanker Sebastian Negri comes in for Alessandro Izekor.
Like Erasmus, Quesada wants to add depth to his squad with only five starters from the final 2025 Six Nations match against Ireland retaining their places.
Gqeberha has not been a happy hunting ground for Italy, who lost 74-3 and 60-14 in previous visits to the "windy city".