South Africa lock Andries Bekker will miss the World Cup with an ankle injury.
The 6ft 10in second rower will have surgery on his ankle next Tuesday, ruling him out of the tournament which begins in New Zealand on 9 September.
The South African Rugby Union said the 27-year-old Stormers player ruptured a tendon at the end of the Super 15 season.
Bekker, the son of former Springbok lock Hennie Bekker, has won 24 caps.
South Africa team doctor Craig Roberts said: "The decision was taken that Andries required surgery now to safeguard his long-term career."
Bekker was a near-certainty to make the 30-man World Cup squad for the defending champions as back-up to first-choice lock pairing Victor Matfield and Bakkies Botha.
Another lock, Johann Muller, will return home from South Africa's Tri-Nations tour to Australia and New Zealand after failing to recover from a hamstring injury.
Muller was withdrawn from the Springboks team for the opening game of the Tri-Nations against the Wallabies in Sydney on Saturday. South Africa had not yet named a replacement for Muller.
The Springboks play defending Tri-Nations champion New Zealand in Wellington on Saturday 30 July.