Rabbitohs lock Cameron Murray.

South Sydney lock Cam Murray wants to build himself up to an 80-minute player – though he admits he doesn't know if coach Wayne Bennett has similar ideas.

Murray has been a standout for the Bunnies through the middle, having inherited the No.13 jersey from Sam Burgess who has made a successful switch to a right edge back row role.

He has scored tries in his team's opening two wins against the Roosters and Dragons, showing a good combination of strength, speed and footwork.

He also has a big motor, currently averaging 30 tackles, 145 metres and 57 minutes – but is aiming for more.

"My fitness isn't quite where I want it to be but it's early in the season, that's to be expected," Murray told NRL.com.

"My focus is just getting as many minutes in the 13 jumper and testing my lungs and trying to get my fitness up and minimising my time on the bench so I can hopefully eventually put in an 80-minute performance in the middle."

Over the opening two rounds, Bennett has substituted Murray around the half-hour mark and brought him back roughly 10 minutes after half-time, meaning the Mascot junior gets a solid half-hour's break.

"I think I'm still a few weeks off [playing a full 80] and I haven't really talked to Wayne about it either," Murray admitted.

Rabbitohs lock Cameron Murray.
Rabbitohs lock Cameron Murray. ©Grant Trouville/NRL Photos

"I don't really know his plans so he's coaching to the conditions and seeing I'm a bit tired there and giving me that 15, 20-minute break on the bench. Hopefully I'm only two or three weeks away (from playing 80) but we'll see what happens.

"That's my focus and I'll be trying my best to push out that 80-minute performance but I'm not going to rush it. I know it's a long season and I know if I trust in the process and the players around me and believe in myself that I can get there so that's my focus leading into the next couple of rounds."

Murray is certainly happy to be starting in the position he feels most comfortable playing and his performances reflect that.

"That's the position I've played the majority of my time in first grade. I'm pretty comfortable there now," he said.

"I've been happy with my performances but I know it won't be that easy going through the season. We're going to come up against some really ruthless opposition that don't make as many errors and don't give us an easy out.

"We need to be more resilient on our line and be able to defend our mistakes and we need to be more ruthless as well. We need to recognise those opportunities to get those repeat sets, to do our best to keep them in their half. There's still a lot to work on."

Murray's performances have been strong enough to put his name firmly in the inevitable early-season Origin bolter conversations, but Murray insisted he had not allowed such talks to distract him from his week-to-week club focus.

Murray also said he had not spoken to Blues coach Brad Fittler about his chances, though there is no question Fittler – who was sideline for Channel Nine during Murray's effort against the Dragons – has noticed the lock's strong start to the year.

"I'm just focusing on playing good footy consistently because I know that's what's going to get me there so if I think about it now and get too ahead of myself I'll get distracted from what I have to do for the Rabbitohs and the boys around me," Murray said.

"A successful team means everyone is putting their hand up for rep positions. We're higher up the ladder and looking better as a team so that's my focus."