Having lost the opening Test of the three-match series against the Springboks last weekend, Saturday's second international takes on even greater importance.
Defeat at Loftus Versfeld would signal the end of the Lions' dreams of a series victory over the reigning world champions. Even a draw would not be enough to see the Lions repeat their heroics of 1997.
Victory is all that matters in Pretoria. Anything less would force the Lions to wait another four years for a chance of a series win over one of the southern hemisphere giants. Worse still, defeat for a second successive weekend would leave the Lions with a 12-year itch to scratch the next time they return to South Africa in 2021.
The size of Saturday's task needs no exaggeration. To say the Lions are up against it would be a simple understatement. The tourists have a mountain to climb to win the two remaining Tests and therefore the series.
Only two other Lions parties have come back from defeat in the opening rubber to claim the spoils overall, and one of those was more than a century ago. In 1899, the Reverend Matthew Mullineux led the Lions to a 3-1 series victory over Australia having been on the wrong end of a 13-3 scoreline in the first Test in Sydney, while 90 years later Finlay Calder's Lions overcame a 1-0 deficit to beat the same opposition.
Such a feat has never been achieved in South Africa, however, meaning the 2009 Lions will have to create their own piece of history if they are to finish with two wins from their remaining two matches.
Add to that the fact that both the second and third Tests will be played at altitude, plus the realisation that there is now no chance of the Springboks being rusty in any way, shape or form, and the extent of the challenge becomes even greater.
Then consider the fact that after 50 minutes in Durban last weekend, and until the Boks made numerous changes, the Lions found themselves trailing by 19 points and seemingly on their way to a serious drubbing and suddenly it becomes only natural to adopt a pessimistic approach to their chances of success.
That is until you step back and embrace the Lions' own perspective, the one championed by coaches, players and even supporters alike in the aftermath of the 26-21 reverse at the ABSA Stadium.
Disappointment may have been the over-riding emotion immediately after the final whistle in the first rubber, but it was countered by a real sense of conviction in the Lions' cause. Not a single member of the Lions party made light of the task ahead but equally no one gave a downbeat assessment of what would be needed to succeed.
Ian McGeechan pointed to the number of try-scoring opportunities created by his players throughout an enthralling 80 minutes, while Warren Gatland praised the character of the side in coming back from 26-7 down to come so close to an incredible triumph. Tour skipper Paul O'Connell felt his side deserved more for their efforts, while centres Brian O'Driscoll and Jamie Roberts were widely praised for their number of clean line breaks.
In short, the Lions' perspective made happy reading bar the result and the setpiece. The Boks may have dominated at scrum time, forcing the Lions to concede a raft of penalties but it was the Lions who looked more dangerous in open play. South Africa may have possessed more power up front but the Lions' line rarely looked threatened. Peter de Villiers' men have appeared in control early in the second half but they were left fighting for the lives in the closing stages.
So there you have it. To the Springbok faithful, the series should be done and dusted come close of play on Saturday afternoon. To their Lions counterparts, the series is still very much alive. Create as many chances as they did last time out, rectify the problems in the scrum, and finish as strongly as they did in defeat in Durban and the men in red will travel to Johannesburg on July 4 with everything still to play.
The Springboks have made just one change to their starting line up for Saturday's second Test, with head coach de Villiers admitting he made a mistake in making so many substitutions at the old King's Park.
Schalk Burger's recovery from a calf injury ensures an immediate return to the first XV for the Stormers blindside, with tryscorer Heinrich Brussow dropping to the replacements bench following an impressive Test debut.
A former IRB World Player of the Year, Burger is a huge part of the Springbok strategy, with de Villiers claiming that 60 per cent of his gameplan as far as the forwards are concerned revolves around the influential 26-year-old.
Burger's return adds even more power to a South African side that bossed the Lions physically for most of the opening encounter, but the demotion of Brussow could have an impact on the speed at which the Boks recycle possession in Pretoria.
Two further changes can be found among the replacements, where de Villiers swaps a hooker for a prop and opts for a five-two split in favour of the forwards. Hooker Chilliboy Rapelle replaces fellow Bull Guthro Steenkamp on his home ground, while Brussow takes the place of scrum-half Ricky Januarie in the No 20 shirt.
That leaves fly-half Ruan Pienaar as scrum-half cover should Fourie du Preez get injured at any stage of proceedings, with the Bulls' in-form playmaker Morne Steyn ready to step in at No10.