This game is everything to Scotland. If they don't beat South Africa they probably won't be in the top eight in the world rankings at the end of the year, which would mean being drawn in a pool with two higher-ranked sides at the 2015 World Cup.
Quite simply Scotland need to win, but I also want to see an improvement from one game to the next. If they do improve certain aspects of their game then they can beat South Africa.
Scotland can take a lot of positives from the New Zealand game. To score three tries against the All Blacks should give them a lot of confidence, as should the fact they were competitive up front. But they still conceded 50 points and lost the Test.
First-phase possession is one thing but it's when they get into the phases that New Zealand come into their own. And while a team won't always exploit mistakes like New Zealand did, if you miss 25 tackles in a match against any international side, you're in trouble.
In certain areas Scotland defended well. It was physical, there was double-hitting and teaming up. But there were some bad examples of trying to drift too quickly.
Ross Rennie and Ross Ford made fundamental mistakes for New Zealand's first try: they had one responsibility and that was to take Dan Carter and they didn't, they drifted instead.
Their role wasn't to make the next tackle, it was to make that tackle on Carter. There's a new defence coach, Matt Taylor, and I imagine his system will take a while to bed in. But whichever system you have, the basic premise is that you make the tackle you've got to make.
Max Evans also missed Carter for the last try and when there is so much movement going on around the ball carrier, if you're thinking about whether to drift or make the tackle or cover the inside pass, someone like Carter will punish you.
South Africa will pose different questions. They are hugely physical and they play with less ambition than the All Blacks. That's not to say they are one-dimensional and can't score good tries, becausee they can. But their approach is very different from New Zealand.
They are more comfortable playing a more limited game, playing to their strengths and their major strength is their physicality. And if somebody is running straight at you, you know he's your man and you're going to have to make that tackle.
Crucially, they don't have a Dan Carter. Pat Lambie is a good, competent stand-off but he's not what you would describe as a flair stand-off. Their centres, particularly skipper Jean de Villiers, are also very direct.
Scrum-half Ruan Pienaar is a key player for the Springboks and was the difference between Ireland and South Africa last week. He has been a revelation for Ulster and is still a key player when it comes to international rugby.
Against Scotland, as against Ireland, Pienaar will probably get a platform because Scotland won't be able to dominate the South African pack. And if this is the case, Pienaar will have plenty of ball and will be able to dictate.
The bedrock of South African rugby is their forward power, it's ingrained in them, and it will require a monumental effort up front by Scotland because of the sheer size and strength of that Springboks pack.
You have to take the game to South Africa. If you try to sit off them and absorb their directness and physicality, you will come off second best. And Scotland proved against the All Blacks that they can maul well, can be physical and take them on up front.
Ross Rennie is a big loss for Scotland in the back-row. He's a really intelligent rugby player, his offloading is excellent and that's a game-plan Scotland are trying to develop. You can get in behind defences with good offloading.
Defensively he was also very good at getting his hands on the ball in the tackle and knowing when to go in and when not to. However, his replacement Dave Denton will really take it to the Springboks, especially with ball in hand.
And if Scotland can get good field position and get into good areas, they've got players to threaten South Africa offensively.
It was great to see winger Tim Visser scoring two tries against New Zealand because we've seen what he's done for Edinburgh and wondered how he would step up.
But what I'd like to see him do more of is come in off the scrum-half or the inside channel from the stand-off and physically challenge the South Africans. He's a big lad, as is Sean Lamont on the other wing, and I'd like to see them be really direct.
If they can do that they will set a platform and allow people like Stuart Hogg and Nick de Luca to get ball in hand in a bit of space. Against South Africa, more than anyone, you need to earn that space.
I don't see this game being a high-scoring affair, it will be a much more conservative game than last Sunday.
But fundamentally, Scotland still have to defend better. Defend as they did against New Zealand and they will lose. It's as simple as that.