Springbok coach Heyneke Meyer has had plenty of time to decide on his final group of 31, but that won't have made the process any easier.
Meyer will announce his 31-man squad on Friday, but there is still a degree of uncertainty about the fitness of several key players.
Captain Jean de Villiers is still recovering from a fractured jaw and should be ready by the time the Boks' campaign starts against Japan on September 19.
However, Marcell Coetzee is in a race against time to be fit for the global showpiece after suffering a knee injury during the Rugby Championship.
Meyer will be sweating over the fitness of several injured players who couldn't participate in Monday's joint training session with Namibia in Durban, with the likes of Jannie du Plessis (knee), Fourie du Preez (knee), Francois Louw (shoulder), Vincent Koch (knee), Steven Kitshoff (knee), Willie le Roux (ankle) and Zane Kirchner (hamstring) all nursing niggling injuries.
Here is who should make the cut.
Props: Tendai Mtawarira, Jannie du Plessis, Trevor Nyakane, Frans Malherbe and Steven Kitshoff
Mtawarira and du Plessis should be the starting props as they have the needed experience to cope in high-pressure situations. Nyakane's ability to play tight and loosehead makes him a solid back-up option for the Boks while Malherbe has shown that he can do the job at Test level. Kitshoff, however is still struggling to recover from a knee injury but his performances in this year's Super Rugby for the Stormers has proven that he is worthy of the green and gold jersey. If he is not fit, Marcel van der Merwe is a handy option to fall back on.
Hookers: Bismarck du Plessis, Adriaan Strauss, Schalk Brits
All three are capable of doing the job but du Plessis has shown in this year's Rugby Championship that he is worthy of the starting position with Strauss set to come off the bench in the big matches. Brits will make an immense impact as a replacement due to his attacking style of play and his experience of playing in the northern hemisphere should benefit the Boks.
Locks: Victor Matfield, Eben Etzebeth, Lood de Jager, Pieter-Steph du Toit
Matfield is rated by many as the game's best ever lineout operator. That and his previous World Cup experience will be invaluable for the Boks. Etzebeth's sheer strength and physicality should also boost the Boks in the heavier northern hemisphere conditions. De Jager has the ability to play both lock positions and has an immense work rate will benefit the Boks at the breakdown. Du Toit can provide cover at lock and blindside flank. However, he still has to regain his confidence and form.
Loose forwards: Schalk Burger, Duane Vermeulen, Francois Louw, Siya Kolisi, Willem Alberts and Heinrich Brüssow
Vermeulen and Louw's physical presence at the breakdown will be invaluable at the World Cup, although Vermeulen is in a fitness race. Burger's experience and his new-found form will boost the Boks as he can also play in all three loose forward positions. Like Burger, Kolisi is at home anywhere in the back row which makes him a must while Alberts should make a telling contribution off the bench. Brüssow should be in the squad as a breakdown specialist which could prove handy up north.
Scrum-halves: Fourie du Preez, Ruan Pienaar, Cobus Reinach
Du Preez picks himself as his experience is invaluable and he should start the big games. Pienaar's experience playing in the northern hemisphere will benefit the Boks and he also provides cover at 10. Reinach's explosive running game will be invaluable as an impact player off the bench.
Fly-halves: Pat Lambie and Handre Pollard
Nothing between these two and both deserve their spots. However, Lambie should be first choice as he has proven to be more reliable with the boot.
Centres: Damian de Allende, Jesse Kriel,Jean de Villiers and Jan Serfontein.
De Allende and Kriel have been the standout performers for the Boks in this year's Rugby Championship. Both have the ability to break the line to create try-scoring opportunities. Kriel can also provide cover at full-back. However, De Villiers' experience and leadership abilities will secure his spot at outside centre with de Allende on his inside. Serfontein can provide cover at inside and outside centre, and his physical presence along with his ability to break the defensive line should be invaluable.
Wings: Bryan Habana, JP Pietersen, Lwazi Mvovo
Habana and Pietersen's World Cup experience will be vital and they should start the big games. However, Mvovo showed against Argentina in Buenos Aires that he is a lethal finisher, solid on defencee and safe under the high ball.
Fullback: Willie le Roux
Le Roux has struggled to find form this season but showed that he can create try-scoring opportunities from almost anywhere on the park. He can also provide cover at wing while Kriel, Lambie, and even Pienaar, are also options as his back-up.
By Ben-Owen Jones