Sinckler, 23, was one of four props retained by Jones along with Dan Cole, Joe Marler and Mako Vunipola.
Flanker Tom Wood is still in contention to make his first appearance under Jones, one of four back-row forwards in the squad along with former captain Chris Robshaw, Billy Vunipola and Nathan Hughes.
The 30-year-old Wood was recalled after injuries ruled out 10 players, including five flankers, for the games against South Africa, Fiji, Argentina and Australia.
Wood's Northampton teammate Teimana Harrison, who was unceremoniously hauled off by Jones in the first half of the third test against Australia in June, was among the players sent back to their clubs.
Jonny May and Marland Yarde are set to start on the wings against the Springboks in the absence of the injured Jack Nowell and Anthony Watson.
Semesa Rokoduguni, who won a solitary cap in 2014 before being dumped by former coach Stuart Lancaster, failed to make the cut despite his great form for Bath this season.
Jones looks set to carry on with his policy of playing Owen Farrell at centre, outside flyhalf George Ford, despite Farrell playing his club rugby for Saracens at number 10.
Uncapped New Zealand-born Ben Te'o also made the final 25, although Jones looks likely to continue with Jonathan Joseph at outside centre alongside Farrell.
England have not beaten South Africa in 10 years and were the only major nation Lancaster did not get a win against - though he did manage a 14-14 draw in Port Elizabeth in 2012.
Either side of that have been 11 defeats, including the 2007 World Cup final. England's last victory came at Twickenham in 2006, the last of a seven-game winning run against the Springboks.
