Souths star Cody Walker believes a top-four finish should be the goal for the in-form Rabbitohs after their 38-0 annihilation of the Eels on Thursday night.

That win moved them temporarily to equal fourth on competition points, although they head into round 17 in sixth after wins to the Roosters and Raiders.

Despite the convincing nature of their past two wins over Manly and Parramatta, Walker said the fact the team had so much improvement still left in them has him convinced the top four should be the target.

"I think [top four] is a realistic goal for us," Walker said.

"We're always chasing to put an 80-minute performance in and I don't think we've done that this year.

"Even last week [against Manly] we came out, they flew out to a 10-nil lead after the break. Then [against the Eels], there's still improvement left in our game. We need to be better."

The Bankwest Stadium effort against the Eels was more impressive for Walker than the one against Manly because it meant the team had backed up one good performance with another one.

Match Highlights: Eels v Rabbitohs

"The challenge is to back it up again next week [against Melbourne]," he added.

"We've got another top-four side. The Storm have been the most consistent side of the last decade."

South Sydney's purple patch has come off the back of maintaining possession and forcing opponents to come out of their corners, which had been particularly good for fullback Latrell Mitchell to build his combination with the halves - Walker and Adam Reynolds - until his ruptured hamstring ended his season on Thursday.

"Reyno's got one of the best kicking games in the comp and we were able to utilise that and back our D. We're not giving penalties out of yardage and the cycle's just working for us. The key to that is doing it for longer periods of time and just do it over and over and over."

The loss of Mitchell is a massive blow, but Walker noted the returning Alex Johnston was more than familiar with the team's systems while playing at the back.

"AJ has played a lot of fullback before in this side and he's fairly comfortable."