Eben Etzebeth has been passed fit for South Africa's World Cup Pool B game with top-ranked Ireland on Saturday as they include 14 starters from the opening win over Scotland.

The defending champions then made 14 changes for the 76-0 win over Romania.

However, they have reverted to the side that started against Scotland, bar injured hooker Malcolm Marx.

Marx has been ruled out of the remainder of the tournament so Bongi Mbonambi will start in the number two jersey against the Irish.

Mbonambi and Damian Willemse are the only starters retained from the Romania win, with the latter moving from fly-half to full-back.

As expected, South Africa coach Jacques Nienaber has opted for seven forwards on the bench, with scrum-half Cobus Reinach the sole back in the replacements.

Reinach will also provide cover at wing, while forward replacements Kwagga Smith has extensive Sevens experience and could also provide a backs option.

Etzebeth will be partnered by Franco Mostert, with captain Siya Kolisi, Pieter-Steph du Toit and Jasper Wiese returning to the back row.

Faf de Klerk and fly-half Manie Libbok unite at half-back, while Kurt-Lee Arendse and Cheslin Kolbe will patrol the wings outside of the centre pairing of Damian de Allende and Jesse Kriel.

Lock Jean Kleyn, who earned five caps for Ireland before switching international eligibility back to his native country, is named among the replacements alongside his Munster team-mate RG Snyman.

Ireland edged a 19-16 victory in their most recent encounter in Dublin last November.

"We're fortunate to have a match-fit squad and have been building depth and versatility for a while and believe this is the best combination for this match," said Nienaber.

"We know it's going to be a grind of a match and we know we need to pitch up physically and mentally."

South Africa: Willemse; Arendse, Kriel, De Allende; Kolbe; Libbok, De Klerk; Kitshoff, Mbonambi, Malherbe; Etzebeth, Mostert; Kolisi (capt), Du Toit, Wiese.

Replacements: Fourie, Nche, Nyakane, Kleyn, Snyman, Van Staden, Smith, Reinach.