Jamie Roberts is key man as Lions aim to level test series

The Welsh centre was one of the Lions success stories in the 26-21 First Test defeat by the Boks in Durban with his punishing running and strong defence.

But, despite all his efforts, three squandered try-scoring opportunities have left the 2009 tourists on the brink of losing the series.

Defeat by the world champions tomorrow means the trip will go down in the record books as a disaster and head coach Ian McGeechan's magic will have failed for the first time.

McGeechan has never lost the Second Test of any series as head coach and has previously enjoyed triumphs in Brisbane and Wellington that kept hope alive after initial misfortune.

In 1989, early injuries left the Lions vulnerable and the Australians were easy winners of the opening encounter but the tourists took the next two matches to claim a series triumph.

Four years later, a dreadful refereeing decision robbed the Lions of a famous win against New Zealand in Christchurch and McGeechan used that injustice to fire up his men to achieve a remarkable win over the All Blacks in the second game, although the series was ultimately lost 2-1.

The dynamics are very different for McGeechan this time; there can be no excuses about injuries or the wrong call by an official - they are trailing South Africa 1-0 because they didn't finish their chances.

As a result, wing Ugo Monye, who saw two chances slip away in the First Test, was dropped in a very public example of what happens to even the brightest and best when they fail to deliver.

Roberts's ability to consistently deliver is why the Boks have brought back fit-again Schalk Burger at flanker in place of Heinrich Brussow, a try scorer in the First Test.

The Springboks are so concerned about Roberts busting their defence, they have given Burger the job of man-marking the Wales centre and it's the kind of task the forward relishes.

Burger is a bull of a man who enjoys the rough and tumble of Test rugby to such an extent he appears to have a manic grin on his face for the entire 80 minutes.

If Roberts can dump Burger on his back early in the battle, it will provide the kind of psychological lift Scott Gibbs gave the 1997 Lions when he knocked over 19st prop Os du Randt.

Given the problems the Lions forwards had in Durban, it will take this kind of individual statement of intent to repair dented confidence particularly up front in a team that, after five changes, is now based around a record seven grand-slam winning Irish players aided by six Welsh and two from England.

The Lions scrum was a disaster of such epic proportions in the first half of last week's Test that prop Phil Vickery and hooker Lee Mears have been left out of the squad and will have seats in the stand at Loftus Versfeld.

The job of handling the Springboks front-row - all of whom play for the Sharks - falls to the Welsh trio of Gethin Jenkins, Matthew Rees and Adam Jones, who are not renowned for their scrummaging.

Instead, their collective skills are needed to ensure a stable platform for the backs to work off.

Tendai 'the Beast' Mtawarira ended Vickery's Lions Test career with his aggressive work at loose-head but with Simon Shaw, one of the strongest scrummagers in the world, providing a shoulder for Jones to rely on, the Lions will not be pushed around this time.

The tourists have sacrificed the perceived line-out skills of Alun-Wyn Jones and called on the ballast and power that Shaw brings to every match and, given the threat posed by the Boks' driving maul, his ability to disrupt this weapon will be needed throughout what promises to be a physically draining contest.

The match is being played at altitude and the Lions have gambled on staying at sea level in Cape Town and are only travelling to Pretoria later this afternoon.

Loftus Versfeld is the home of the Bulls, the Super 14 champions, and is deemed by Lions defence coach Shaun Edwards to be the toughest place to try to win a match in world rugby.

The rarefied air is one of the main problems for visiting teams and, despite having used breathing masks to replicate training at 7,500ft, the Lions could well be affected by the conditions.

At least Roberts and his fellow backs will have a dry ball and hard ground to perform on, unlike their training in Cape Town, where gale-force winds and driving rain have been a factor.

It all contrasted starkly with the Springboks, who based themselves in Johannesburg at altitude for the week.

A Lions victory will save the tour and turn next weekend's decider in Johannesburg into one of the most eagerly awaited matches in rugby history but the Springboks have more power and pace and only their own arrogance - which allowed McGeechan's men to fight back last Saturday - will stop them clinching the series 2-0.