Nathan Cleary and James Maloney.

Panthers halfback Nathan Cleary is unlikely to play in the trial against South Sydney this weekend but has confirmed both a tactical swap with five-eighth James Maloney and the team's fullback.

With Dallin Watene-Zelezniak starring at fullback for New Zealand in the post-season, there was a question over whether he would displace Dylan Edwards – who started last season at the back before being injured – in the No.1 jersey.

But with Watene-Zeleaniak still coming back from his own knee injury – he underwent surgery in January – the race was over before it began, according to Cleary.

"I think Dyl will have that fullback spot locked down just because Dal has been injured and just coming back now," Cleary said on Monday.

"We've had a lot of reps with Dyl back there and he was obviously the fullback to start off with last year."

Cleary was less convinced who was winning the No.9 race between Sione Katoa and Wayde Egan.

"That hooking role, there's kind of a good battle going on but I've played with both of them and thoroughly enjoyed playing with both of them as well growing up, they're both great players and whoever gets put in there will do a great job," Cleary added.

"I think it will come down to trials to see who takes it out."

Cleary said the decision to swap from the right edge to the left alongside Viliame Kikau and Waqa Blake which resulted in Maloney moving to the right next to defensive maestros Isaah Yeo and Dean Whare was made by coach Ivan Cleary.

"I think Dad came up with it just from watching us last year and wanted to try something new," the younger Cleary said.

"Billy [Kikau] and Waqa are a bit inexperienced on that left side and Jimmy defends really well next to Deano and Yeoy, they've got a good understanding.

"It's something different, we'll have to see how it goes. I think that is definitely locked in for round one, it's what we've been doing the whole pre-season. It's coming along well but there's still a long way to go."

Cleary wasn't expecting to play this weekend against the Rabbitohs because he has only been back in full training for around three weeks after having been granted permission to delay off-season ankle surgery to enjoy a holiday in Bali and Thailand.

"I'm just happy to be back in training – I think it's been about three weeks," he said.

"I don't think I'll play too much [in the trials], I probably won't play this weekend, maybe get a couple of minutes against Parra but we'll just see how that goes. I don't want to rush into anything too soon and try and be 100 per cent right for round one."

Once he is back on the field, he will get the chance to line up alongside the all-Fijian pair of Blake and Kikau.

"It's good defending next to big Billy and in attack it's unbelievable, just get him the ball," Cleary said.

"We're working on a few combinations there, I've been thrown into the Fijian edge with him and Waqa. They're lightning and really enjoyable to play alongside. They're really keen to learn and get better as well.

"[Kikau] showed a fair bit of that last year but I think he's still got strides to come, he could be anything, big Billy. That's why I'm enjoying playing alongside him."