Newcastle players weren't sure if Jermaine McEwen was brave or mad when the fiery back-rower made it his mission to go after Penrith enforcer Moses Leota.

McEwen forced an error from tough-nut Leota midway through the first half of Sunday's preliminary final before sarcastically taunting the Panthers prop for his rare blunder.

Leota - one of the game's most-feared front-rowers - didn't appreciate McEwen's behaviour, and sparked an all-in melee when he squared up to the 21-year-old Knights forward.

McEwen had the last laugh and wants to bring a similar intensity to Sunday's grand final at Accor Stadium against the Sydney Roosters.

"There's a lot of respect for Moses and the boys from Penrith, but Moses is like me, he builds his game on aggressive plays," McEwen told AAP.

"I want to bring that energy and that presence and I thought I'd try to get under his skin and into his head. I maybe didn't get into his head, but I know I gave the boys energy.

"I feel like a lot of boys feed off my energy, but as a younger one going after one of their most experienced players, they knew they had my back and that's what kicked it off."

McEwen's fearless antics drew the admiration of his fellow forwards, including workaholic lock Mat Croker.

"That's the mentality of our young boys at the moment, we've got a lot of boys that don't have the scars of the bad years and losing finals," Croker said.

"All they know is being excited for a game, to go out and they play fearless, and it's paying off for us at the moment.

"I think that's why it's so rewarding, our young boys have stepped up with so many players out and we have found our way into a grand final, it's a pretty cool story."

McEwen, who has formed a devastating partnership with fellow youngster Francis Manuleleua in the back row, will have plenty of hot-headed Roosters in his sights on Sunday.

Manuleleua, 22, said he thrived off watching his fellow edge forward take it to their opponents.

"I love his aggression, and you saw it with how he forced that error from Moses," Manuleleua said.

"He started cheering in his face and that's what we want, we want the other team to know that we're up for it, we're coming for their heads.

"We want them to know we won't back down, even if they're the benchmark of the NRL."

Australian Associated Press