North Queensland Cowboys' rookie Helium Luki has been slapped with a Grade 2 careless high tackle charge which will rub him out of at least one game unless he can overturn it at the NRL judiciary.

The young forward, who made his debut in Round 11 against the Newcastle Knights and has only made a handful of first-grade appearances, was placed in the sin bin during the Cowboys' horror loss to the South Sydney Rabbitohs in Newcastle on Friday evening.

The shot on Peter Mamouzelos saw the Rabbitohs' rookie go for a head injury assessment, which he ultimately passed to make it back onto the field.

Luki is facing a one-game ban from competition should he take the early guilty plea, however, if he elects to fight and loses, the suspension will go to two games, meaning he would miss games against both the Roosters and Storm in the next fortnight.

The match review committee's decision will baffle Cowboys' fans, given Liam Knight has only been fined for a similar shot just moments earlier.

Knight's hit wasn't penalised on field, only placed on report after a tip-off from the bunker, with Luki's sin binning coming in the next passage of play.

Taane Milne was also fined for a careless high tackle out of the game.

The suspension and sin binning of Luki only adds insult to injury for the Cowboys, who once again squandered an early lead. After getting away to a 12-2 lead, they conceded 44 points to 6 in the final 60 minutes of the game.

Payten said the problems were self-inflicted.

“We made a mistake there at the 25-minute mark – poor pass into a dropped ball, then we compound that by not defending our line – so we’re just an immature team at the moment,” Payten said.

“We’re just not willing to pay a price in the tough parts of the game for long enough.

“I thought Jason and ‘Macca’ (Jordan McLean) were pretty strong but they need some assistance by some key players around them and some more experienced guys.”

Coach Todd Payten was visibly frustrated with his team, both at halftime and fulltime. With two of the competition heavyweights on the agenda in the next fortnight, North Queensland may make changes in an attempt to scrounge an upset as they attempt to hang in contention for the top eight.

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