Maguire was punted on Tuesday after facing a board meeting and told his services were no longer required.

The 43-year-old delivered the club its first premiership in 43 years in 2014, however, after successive 12th-placed finishes the past two years, the foundation club decided to go in another direction.

Siebold, who has signed a two-year deal with South Sydney, thanked Maguire for his guidance.

"Having worked under 'Madge' this last 12 months, it's been a great opportunity to learn from him," Seibold said on Thursday.

"I've known Madge for 20 years, we worked together at the (Canberra) Raiders back in 1998 so it's been a really challenging last 24 hours.

"Our family's very good friends with Madge, (Joelle) and the kids. I had a conversation with Madge yesterday afternoon, it was a tough conversation to have.

"But he was really supportive of the opportunity that's been presented to me. I am indebted to Madge for the last 12 months, and he leaves a great legacy here at the Rabbitohs."

Rabbitohs general manager of football Shane Richardson said after working as an assistant at Melbourne, Manly and South Sydney, Seibold was qualified to start his journey as an NRL coach.

"Anthony has done a long apprenticeship with some of the best coaches and organisations in rugby league and we believe he is the man to take our team to the next level," he said.