Barker was released by Usuthu after the National First Division outfit failed to seal an immediate return to the Absa Premiership in 2015/16.
Zimbabwean tactician Joey Antipas has since taken over the reins in Durban.
"This short break from coaching has allowed me to reflect and refresh myself both from a personal and professional level. I have regained my passion, hunger, desire and commitment to coaching," said Barker, who spent six years in charge of University of Pretoria prior to joining AmaZulu in November 2014.
Barker's agent John Wilson added: "Steve is a fantastic coach who has done a lot for South African football, especially when you look at the players he has promoted. He has been a great mentor to his players and I am excited to see where he will go next."