Bennett has a dilemma over his centres

South Sydney coach Wayne Bennett says he has a difficult choice to make at right centre after the sterling performance Campbell Graham put up in the 31-10 Rabbitohs win over the Warriors.

There were some standout individual performances from the Rabbitohs, led by  NSW forward Cameron Murray scoring a double. But Graham starring in his first start at centre can't be under-estimated.

Filling in for the suspended James Roberts, Graham ran for 218 metres, made three line breaks and busted through seven tackles.

Bennett said it leaves him with a difficult decision when Roberts returns from a two-match suspension for the first week of the finals.

"We have got to get through next week [round 25] without James Roberts, so that's a decision I have got to make," Bennett said.

"[Graham] was very good tonight and he will get confidence out of that."

Bennett praised his side putting plenty of starch in their defence as they prepare for the Roosters next Thursday at ANZ Stadium and then the NRL finals.

Bennett's men stayed in the grind and kept the home side scoreless in the second half.

Souths raced to a 14-0 lead after half an hour, but had to endure a rough patch five minutes before half time in which the Warriors scored twice to reduce the deficit to four points at the break.

But the Rabbitohs were ruthless in their response, outscoring their opponents 17-0 in the second period to keep themselves in the race for a top-four spot.

After watching his men trade tries with the Broncos in a rollercoaster encounter last weekend, Bennett said it was pleasing to see his players finally stamp some authority.

"The way we kept them out of the game for most of the game, it's not something I think we have been good enough at," Bennett said.

"They knew what our goal was tonight and how we wanted to play.

"They did it for 33 minutes really good and then came out in the second half and started it all again and stayed at it for 40 minutes.

"We are doing a lot more things right than we are doing wrong [right now].

"I couldn't be much happier going into where we have got to go now, Roosters on Thursday night and then into the semi-finals."

Prop Liam Knight, who ran for over 110 metres in the win, said it served as further proof that the side has come out of their post-Origin slump, and was a positive sign ahead of facing the second-placed Roosters.

"We struggled after Origin, we dropped off a little bit in key areas, the hard stuff, but we have got back to that recently," Knight told NRL.com.

"We had a big chat a couple of weeks ago… we have been in the top-four all year, it was just about changing our attitude and our mentality, so when we get in that fight we have the mentality to stay in it.

"I am very excited for the Roosters, they are a quality team but hopefully we can get a win over them and secure a top-four spot and get a bit of confidence before the finals.

"There's no bigger test, I think it's the best thing that can happen to us right now."