By SABC Sport
19th September 2023
South Africa first used the tactic in last month's World Cup warm-up match against the All Blacks when fullback Willie le Roux pulled out late on and was replaced by Kwagga Smith in the squad.
When quizzed about whether there could be surprises in their team selection this week with some suggesting that Springbok coach Jacques Nienaber could opt for only one or even no backline replacements on the bench, Erasmus said: "I don't think we can go 8-0; that would be a bit extreme. But 7-1 is definitely an option, and we are considering that.
"I think there is a lot of teams doing really innovative things; we saw a lineout this weekend, I think it was Portugal, a fantastic old-school lineout.
"I think sometimes when you do things you did many years back, people see it as innovation, but it's just stuff that you remembered that worked way back.
"Obviously, the 7-1, a couple of years ago, the 6-2 was very new to people, a lot of teams are now doing 6-2.
"If you go 7-1, you have to have players like Kwagga Smith who is used to playing Sevens or able to play against Fiji and guys in one-and-one situations.
"But then again, you've got Johnny Sexton and Conor Murray or, I'm not sure which number nine will play (for Ireland), that can exploit you when they get it in the air and every area of the game."
Ireland's ability to hold onto possession and launch multi-phase attacks is incredibly difficult to combat, but Andy Farrell's side are coming up against the premier defensive system in the game this weekend.
South Africa did superbly to limit Scotland to just three points during their opening Pool B clash, and Erasmus is hoping to negate the Irishmen's strengths in Paris on Saturday.
"I think the other thing we can do is really try and beat Ireland at what they do really well, which is a beautiful attacking game, with a solid defensive system," he added.
"Technically, they're a really sound team. I don't think there are any weird tactics that will help us with this game.
"We know what we have to do if we want to beat Ireland. We have to knuckle down, and give everything because they have a good attacking and defensive game and technically they are very sound."