The Rabbitohs, who have already lost three games by two points or less this season, are preparing for a tough grind against a Dragons outfit renowned for winning games at the back end of matches.

Souths coach John Lang this week spoke to his troops about their inability to close out tight matches, a problem that Champion described as a "mental issue".

"We addressed it the other day in our review session," he said.

"You've got to learn from your mistakes, so hopefully that Roosters game can prove a learning curve for us."

While Souths have lost several games by small margins, their record of winning margins is one of the best in the competition.

The Rabbitohs have won eight games this season, six by margins of more than 18 points.

In past seasons, the Bunnies have been criticised for their attack - or lack of - but Champion believes a consistency in the halves has boosted the team's strike power.

"It helps enormously, especially with the confidence and belief within the group," he said.

"Everyone knows what they are doing because we haven't got guys going in and out like we have had in the past.

"You get to build combinations with players like Chris (Sandow) and John (Sutton)."

The Rabbitohs have a challenging final eight weeks of the regular season, but with 20 points after 18 rounds, they are in a position to reach the club's second semi-finals since 1989.

But Champion isn't resigned to making up numbers in this year's finals campaign and said his side had the "belief" to go all the way.

"No team starts the season hoping to just make the top eight," he said.

"You bash yourself up and compete as hard as you can each week, and you want to aim for something at the end of the tunnel - and that's a premiership.

"I know there is the belief here among the players."