In the NRL's land of the giants, there is little separating them physically. Mentally, Bryce Cartwright and Viliame Kikau could hardly approach the game more differently.

Boyhood behemoths, they will start on the left edge for their respective teams when the Titans host the Panthers on Friday night yet they will impact their teams in very different ways.

A rare combination of size and skill made Cartwright a junior five-eighth with very few peers but with a physical advantage that would count against him when he reached the highest level.

Like Ben Simmons not seeing the need to develop a jump shot until he reached the NBA, an 11-year-old, 6-foot-tall Bryce Cartwright could 'bear hug' any kid brave enough to run near him and effect a tackle.

He didn't have to run hard or tackle hard to be effective in his formative years and now, at 24 years of age, they are hard attributes to teach.

Kikau, on the other hand, grew up on the tiny Fijian island of Bau fighting for every small advantage he could get.

When he was recruited by the Cowboys in 2014 he sent shockwaves through the under-20 ranks, tearing teams to shreds using unparalleled speed and footwork for a man measuring 195cm and 119kg.

Last year Kikau was fifth in the NRL for post-contact metres with 1358 and 11th for tackle breaks with 105, with much of Penrith's brilliant attacking bursts inspired by the chaos he created.

By scattering defenders left and right Kikau was able to promote second-phase play with 44 offloads – fourth in the NRL last season – and generate momentum for his playmakers.

Now a starting back-rower, it's a lesson that Cartwright knows he should take.

Like his uncle John before him, Cartwright is renowned for his ability to provide an offload but his days as a five-eighth mean they often happen before the defensive line. A shrug away from a defender and a one-handed release to a teammate in support, the defensive line able to move up as one with minimal disruption.

With points hard to come by in the opening four weeks, Cartwright is the Titans' wildcard capable of creating try-scoring opportunities but first he needs to use his 191cm, 107kg frame to put the defensive team on the back foot.

"I've come through playing five-eighth and doing a lot of passing before the line and kicking," Cartwright told NRL.com.

"I will probably choose that rather than push through the line but that's definitely something I need to work on in my game. Running the ball first, bending the line and getting quick play-the-balls for our creative men.

"When Billy (Kikau) came down from the Cowboys he had a really bad ankle injury and missed a lot of training but when he was playing he was still tearing teams apart.

"He was something like 125 kilos but he could run like an outside back. That's pretty scary when you've got to get in front and tackle him."

Titans v Panthers - Round 5

Titans fullback Michael Gordon has known for a long time that Cartwright had the capability to cause carnage.

Working as a teacher's aide at Bennett Road Public School in Colyton in 2006, the former Panther had a "man-child" by the name of Cartwright in his Year 6 class.

Thirteen years later, Gordon says Cartwright is much the same size as he was then and could use it better to challenge the line.

"He's got so many skills but sometimes he probably just needs to tuck it under the arm and run as hard as he can," Gordon said.

"He's a big boy and I feel like he's been defending really well and playing really solid.

"Carty's a pretty relaxed, chilled-out sort of fella so even if you fire up at him he doesn't really react. He's not one to go around bashing his head with a ball like 'Wal' [Jarrod Wallace]."

A knee injury in Penrith's final trial kept Kikau from making his first appearance for the year until last Friday's win over the Wests Tigers and his impact was immediate.

Denied what NRL Head of Football Operations Graham Annesley later declared was a fair try, Kikau will be better for his 77-minute run, which Cartwright knows spells trouble for a Titans team desperate for their first win of the year.

"We've seen what he can do when he's fully fit. He's pretty much unstoppable," Cartwright said.

"It probably rattled them a bit, him being out, because they used him so much last year and he was such a strike for them."