Fly-half Handre Pollard and centre Lukhanyo Am have been left out of South Africa's 33-man Rugby World Cup squad through injury.

"This was one of the hardest selections we have ever had to make," said Springboks head coach Jacques Nienaber.

Captain Siya Kolisi, 32, has been included having not played since April after he tore the anterior cruciate ligament in his right knee.

"Any of the 42-man training squad would do a great job, but injuries have played a part in the final selection and time unfortunately ran out for some real champions," added Nienaber.

Lood de Jager is another notable omission due to a chest problem, but the Sale Sharks lock joins both Pollard and Am on a six-man standby list.

South Africa begin the defence of their title against Scotland on 10 September.

Pollard, 29, has not played for the Springboks since last August and injured his calf when playing for Leicester in the Premiership semi-final against Sale.

After impressing in the Rugby Championship, fly-half Manie Libbok - who has only seven caps, is the only specialist fly-half in the squad - although utility back Damian Willemse, 25, is also able to play there.

Am, 29, injured his knee during the Springboks win over Argentina last weekend and has also been ruled out of the squad, with Harlequins centre Andre Esterhuizen named.

De Jager - another member of the 2019 World Cup-winning squad - was a late withdrawal last weekend due to illness and misses out on the 2023 edition.

Munster lock Jean Kleyn, who played for Ireland at the 2019 World Cup, was included after recently making his Springboks debut in the Rugby Championship.

Head coach Nienaber has named four scrum-halves with Faf de Klerk, Jaden Hendrikse, Cobus Reinach and Grant Williams all travelling to France. Winger Canan Moodie, 20, also makes the final squad.

The Springboks' second pool game is against Romania on September 17 before they face Ireland and Tonga.

South Africa squad

Forwards: Steven Kitshoff (Ulster), Vincent Koch (Cell C Sharks), Frans Malherbe (DHL Stormers), Ox Nche (Cell C Sharks), Trevor Nyakane (Racing 92), Bongi Mbonambi (Cell C Sharks), Malcolm Marx (Kubota Spears) Eben Etzebeth (Cell C Sharks), Jean Kleyn (Munster), Marvin Orie (Perpignan), RG Snyman (Munster), Pieter-Steph du Toit (Toyota Verblitz), Siya Kolisi (capt, Racing 92), Kwagga Smith (Shizuoka Blue Revs), Marco van Staden (Vodacom Bulls), Duane Vermeulen (SA Rugby), Jasper Wiese (Leicester), Deon Fourie (DHL Stormers), Franco Mostert (Honda Heat).

Backs: Faf de Klerk (Canon Eagles ), Jaden Hendrikse (Cell C Sharks), Cobus Reinach (Montpelllier), Grant Williams (Cell C Sharks), Manie Libbok (DHL Stormers), Damian Willemse (DHL Stormers), Damian de Allende (Panasonic Wild Knights), Andre Esterhuizen (Harlequins), Jesse Kriel (Canon Eagles), Kurt-Lee Arendse (Vodacom Bulls), Cheslin Kolbe (Suntory Sungoliath), Willie le Roux (Vodacom Bulls), Makazole Mapimpi (Cell C Sharks), Canan Moodie (Vodacom Bulls).