Aled Walters has been released from his contract as South Africa head of athletic performance.
The Welsh fitness guru has been with the Springboks since 2018 and will return to the United Kingdom to join English side Leicester Tigers.
"These are uncertain times," said Walters.
"The wish to be closer to families based in Wales and Ireland was a key consideration in making what was a very hard decision."
Walters - who will be head of physical performance at Leicester - has worked at Scarlets, the Brumbies in Australia, Taranaki in New Zealand and Munster.
It was at the Irish province that the Carmarthen-born coach worked with South Africa's current World Cup-winning boss Rassie Erasmus, leaving Munster to join the Boks in 2018.
"I grew up a staunch Scarlets fan and have a lot of history with Leicester, I was there when the famous Tim Stimpson penalty went over," Walters told the Tigers website.
"You have to fit the culture and I definitely appreciate that. That's why teams like Leicester are more attractive to me.
"Leicester is a very similar club to Munster and Scarlets - it's a working-class area, they're tougher people and that's something that definitely appealed to me."