The first five-eighths who now plays for Leicester Tigers in England's Premiership told the For The Love of Rugby podcast that Erasmus' ability at keeping players focused and grounded was behind their success.
As a result, there was no room for complacency among the players.
"The first thing he ever spoke about was entitlement. That's the first thing that breaks a group up if senior guys think they are important.
"That was way back when he started [late in 2017], and it's still something we live by.
"The influence that the older guys have on a group is so big. We've got a very different experience from our younger days to what we are giving the youngsters now. It's different eras.
"It keeps everybody very equal and extremely hungry – especially the old guys, your big dogs like Pieter-Steph [du Toit], Siya [Kolisi] and Eben [Etzebeth].
"It's not a feat of if I'm still going to play or not. It's that, I've got to prove myself every single day, otherwise I won't play. It doesn't matter who you are. That's what makes him special."
South Africa ended 2024 as the No1 ranked side in the world for the fifth time in six years. It is the 10th year they have been No1 since the rankings began in 2003.
The Springboks have been No1 for 250 weeks, still well behind the All Blacks, who have the record with 743 weeks at No1.