Foster said playing the Springboks as their last warm-up for the World Cup was a great way to test themselves. It was better than having a Test where the build-up was as intensive.
"The build-up is great for this. We know we have to match the intensity of a South African team so we have to turn up and get ready, and that is what we want."
The management has named two locks in their 6:2 split on the substitutes' bench, something Foster said they had not done before. But he explained it was a squad management technique. They could utilise their locking cover with lock Brodie Retallick and flanker Shannon Frizell out of action.
Foster said both Retallick and Frizell were recovering well and ahead of schedule.
"We want to take advantage of our locking stocks, and we're utilising Josh Lord while he is over here, and it gives us a good chance to manage the time that Scott [Barrett] and Sam [Whitelock] have.
Foster said he wouldn't be protecting anyone. World Cups were not won by putting people in cotton wool.
"Some things are part of the game. If you go in worrying about the consequences, you go in half-hearted, and those things are almost guaranteed to happen.
"The same thing is going to happen in the World Cup. You don't want injuries in any game. This is ideal for us. It's a big game, we've acclimatised into Europe and it's the sort of build-up we need to make sure we keep climbing our performance levels. The only way to go into this is full throttle."
With blindside flanker Shannon Frizell unlikely to be ready for the opening World Cup game against France, the chance to play Luke Jacobson was an example of what could be expected during the campaign.
"This is exactly the scenario that we expect to have later on so to have them now is great. Luke's a quality person, he's contributed well and played well off the bench. I can't wait to see him play."
Foster said he had enjoyed the reaction to the news of Steve Hansen's work with Australia. Hansen had spoken to him a month ago about what he was doing. From what he saw, Foster quipped that Hansen had promised him three pages of notes.
"There's no lack of trust at all from his commitment to us and what we do, and sharing stuff but there's no issues. We might bring him in for a couple of days ourselves."