DEFENCE may win Six Nations titles but aggression alone won't end Wales' nightmare run against the southern hemisphere big guns this afternoon.

The nation is braced for another disappointment against South Africa at the Millennium Stadium and if Heyneke Meyer is beaming at the final whistle then it will be a 27th failure from 28 games against the big three under coach Warren Gatland.

The stats are well known, as are the dates of 1953 (All Blacks), 1999 (Springboks) and 2008 (Wallabies).

Of course there is hope that South Africa can be beaten for a second time but the Welsh public, just like supporters of Newport Gwent Dragons after a grim 2014, are weary.

The same blueprint that has failed so often will be adopted despite Wales needing a bit more spark.

That means plenty of responsibility on the shoulders of centre Jonathan Davies, who cut the South Africans to shreds in the opening stages last autumn before being forced off by injury.

There was plenty to admire from the performance of Sam Warburton and his team against world champions New Zealand last weekend but Wales desperately need to ask more questions in attack.

It's not often that All Blacks look dodgy with ball in hand but they racked up the errors when faced with a snarling home defence.

But Wales produced little of note in attack and the tank inevitably ran dry after all their exertions in limiting the tourists to a Julian Savea try. Four more followed in the closing stages.

They cannot afford a repeat against a powerful South African side that will keep things simple at the Millennium Stadium in a bid to end an iffy European tour on a high.

The Springboks are without a number of stars but their massive pack features Tendai Mtawarira, Bismarck du Plessis, Eben Etzebeth, Victor Matfield and Duane Vermeulen while behind there is the experience of Jean de Villiers, spark of Jan Serfontein and Willie le Roux and finishing ability of Cornal Hendricks and Lwazi Mvovo.

Their prime weapon will be the driving lineout – the method they used to get themselves back into June's dramatic second Test in Nelspruit – so Wales' discipline will be key.

Give the Springboks territory and they will grind their opponents down, so in-form half-backs Rhys Webb and Dan Biggar must manage the game well and avoid gifting space to Le Roux while Wales must be squeaky clean at the breakdown and scrum.

It promises to be a massive afternoon for a quartet of home players as they attempt to impress in World Cup year.

Scott Baldwin will sink or swim as deputy to Richard Hibbard, who is on Aviva Premiership duty with Gloucester, and Ken Owens, who is sidelined by injury.

The Ospreys hooker's lineout work has been shaky this autumn and won't be helped by the intimidating presence of Matfield while his scrummaging will come under close scrutiny from du Plessis, a brute of a bloke who will also rampage around in the loose.

Jake Ball has had a good autumn and has the chance to solidify his position next to Alun Wyn Jones in the second row – another good display against arguably the best partnership in the world of Etzebeth and Matfield will go a long way towards staying ahead of Luke Charteris, Bradley Davies and Ian Evans in 2015.

Liam Williams, one of the bright sparks from the Fiji win, has another chance thanks to George North's concussion and the Scarlets man will attempt to at least force Gatland to consider breaking up his inked-in back three.

And Gethin Jenkins needs to produce a performance to rival his majestic display in Nelspruit. The loosehead is creaking a bit, prompting fears that he is going the same way as Adam Jones, and needs to stand tall in the absence of Bath's Paul James and injured Ospreys tyro Nicky Smith.

Other than that it's a side that will, injury permitting, line up against England and Australia in the World Cup when the heat will really be on.

For all the talk of pressure there is no danger of Gatland getting the boot but he needs a win to show there is substance to his talk of Wales being in good shape for next year.

Wales: L Halfpenny, A Cuthbert, J Davies, J Roberts, L Williams, D Biggar, R Webb, G Jenkins, S Baldwin, S Lee, J Ball, A W Jones, D Lydiate, S Warburton (captain), T Faletau. Replacements: E Phillips, A Jarvis, R Jones, L Charteris, J King, M Phillips, R Priestland, S Williams.

South Africa: W le Rous, C Hendricks, J Serfontein, J de Villiers (captain), L Mvovo, P Lambie, C Reinach, T Mtawarira, B du Plessis, C Oosthuizen, E Etzebeth, V Matfield, C Coetzee, T Mohoje, D Vermeulen. Replacements: A Strauss, T Nyakane, J Redelinghuys, L de Jager, N Carr, F Hougaard, H Pollard, D de Allende

Referee: John Lacey (Ireland)