In a bid to plug the Panthers' leaky left-side defence from last year, Ivan will experiment with swapping Nathan and James Maloney in the defensive line early in 2019.

While the biggest change at Penrith over the summer has been in the coach's box, the subtle move could pay off for the title hopefuls.

"Yeah, we swapped that up. I'm on the Fijian edge now and Jimmy's gone over to the other edge so it's a bit different," Nathan said on Monday.

"It's pretty cool playing next to someone like Viliame Kikau and Waqa Blake, and then you've got (Josh Mansour) on the wing, who says he's Fijian as well."

The decision to swap sides comes after Maloney and Kikau averaged 6.1 and 2.3 tackles last season on a left-flank that was heavily targeted by rival attacks.

Nathan claimed Maloney had plenty of success defending on the right edge last year before making the move to the other side of the field.

"Jimmy was defending really well next to Dean Whare early in the year. We swapped and had trouble with combinations with Kiks and Waqa," Nathan said.

"They were both new to that left edge.

"(We're) just trying something different and seeing if it'll work out. Jimmy with the experience next to Isaah Yeo and Deano on the other side, it's pretty solid."

Maloney believes the change will also benefit his kicking game.

"They asked me if I could play on the right, and I can play on the right. There's not much change there other than the side of the field I'm playing on," he said.

"I've got Deano over there, we've played a lot together. It's just getting a new combination with Yowie instead of Kiks.

"But that suits me, it makes kicking easier on the right side."

Panthers fans will have to wait at least another week to see how it looks, with Nathan set to be rested from this week's opening trial against South Sydney.

After undergoing ankle surgery in the summer, Nathan only began full contact training a fortnight ago but is likely to suit up in their final trial against Parramatta.

Youngsters Jarome Luai and Tyrone May are expected to partner Maloney against the Rabbitohs at Redfern Oval on Saturday evening.

"Young Jarome's there, he's just itching to go and ready-made if one of us aren't available. And Tyrone May can jump in and a few other guys," Maloney said.

Australian Associated Press