Kolisi first encountered the coach while in the Western Province academy, and has previously credited Nienaber, and South Africa’s director of rugby Rassie Erasmus, with transforming his career.
And in the aftermath of the final victory, Kolisi hailed both the human and coaching qualities of the departing coach.
"It hasn’t been an easy journey,” Kolisi said. “I can’t believe what we’ve achieved today.
“The coaching staff have been ridiculous. I have worked with Jacques since I was 17 years old. I couldn’t tackle. When him and Rassie [Erasmus] used to come to training it was full contact. You had to show that you could do this.
"We grew up around him - me and Frans [Malherbe], Steven Kitshoff and Pieter-Steph [du Toit]. We all played under Jacques. As I said last week, he cared about us as people. He took us further. He asks me, ‘are you going to let your daughter down, your son down?’ It became far deeper than just a rugby game.”
Having begun his career in professional rugby as a physiotherapist and strength and conditioning coach, Nienaber was given his first opportunity as a technical coach by Erasmus with the Stormers in 2008.
He was South Africa’s defence coach in 2019, assembling a fearsome defensive unit built on suffocating linespeed and fierce tackling.
That defence was at its best in the final, shutting down the All Blacks’ versatile attack with Du Toit leading the way with a magnificent individual performance.
Kolisi believes that it is Nienaber’s ability to look beyond his players’ abilities as rugby players that makes him special.
Siya Kolisi believes Jacques Nienaber’s human qualities make him special— (Getty Images)
"Jacques, honestly, it’s been a huge honour for me and a huge privilege,” continued the flanker. “I appreciate you. We love you as a team, not as a coach, but as a person.
“You’ve taken it to another level. The way you speak to us - it’s not ‘make a big hit, make a tackle’, you talk to me as a person, as a father, a husband, as a son, it goes such a long way so thank you.
“We honour you as a team. I hope you are proud of us. They will be lucky to have you wherever you go."