South Sydney coach Michael Maguire says the Rabbitohs self belief remains rock solid despite the NRL side hitting its lowest ebb during his three-season reign.

Successive losses to Manly, Wests Tigers and Canberra is the club's worst losing streak since Maguire moved to Redfern ahead of the 2012 season.

Souths have qualified for back-to-back preliminary finals under Maguire, but the former Melbourne assistant now faces his greatest test to date at the Rabbitohs.

After an impressive first round win over premiers the Sydney Roosters, Souths have struggled for form and Maguire has responded by ringing in the changes for Saturday's round five clash with St George Illawarra at the SCG.

John Sutton has been reunited with Adam Reynolds in the halves, a combination that has been so successful for Maguire over the last two years. Experimental five-eighth Dylan Walker has been shifted back to the centres, with veteran winger Lote Tuqiri dumped and Sam Burgess moving to lock from the front-row.

Maguire says working through the tough times is part of the fabric at the foundation club.

"Sometimes when you are looking at trying to tinker with improvement, it brings a bit of a change in mentality and we need to understand what our strengths are," Maguire told AAP.

"The challenge is there. In your coaching life, in your playing career you go through tough periods.

"This club itself has gone through some tough times so at the end of the day that is inbuilt in this club to be able to keep working hard and to go through those periods and that is exactly what we are doing.

"We still hold a lot of belief, as a group we have been through a lot together and they have built where we are right now, a lot the players have been a part of that."

Maguire admitted Souths need to remember what has helped to make them an NRL powerhouse over the past two seasons.

"We just need to hone in on the things we have build this team on, hard work, areas there in defence under pressure that we pride ourselves on," he said.

"We have pushed passes we don't normally push.

"I wouldn't say we have gone away from those things, things just haven't really worked for us.

"It is just a matter of building on the things that we know work."