Sydney Roosters prop Spencer Leniu has been suspended for eight weeks for a racial slur directed towards Brisbane Broncos star Ezra Mam.

Leniu pleaded guilty to a contrary conduct charge from the match review panel after the Roosters faced the Broncos in their season opener in Las Vegas.

He was sent straight to the NRL judiciary for a sentencing hearing, where he was accompanied by the Roosters' legal team and coach Trent Robinson.

The judiciary panel unanimously agreed on the eight-game ban.

They acknowledged his remorse, his attempts to make an apology in person and that it was a spur-of-the-moment comment, but rejected arguments that Leniu was completely unaware of the racist meaning behind the slur and it should be considered a serious offence.

Mam did not attend the hearing, where the panel reviewed match footage from the game in Las Vegas, but he did provide a written statement, part of which was read by the NRL's legal team.

In his statement, the Torres Strait Islander man said he "was so angry" when he heard Leniu call him a monkey that his "mind was no longer focused on the game".

Leniu, who arrived from premiers Penrith in the off-season, tried to brush off the incident in a post-match interview, telling Triple M "it's all just fun and games on the field" and saying he was "not worried at all".

But he told the judiciary he regrets his actions and said at the time he was not aware of the meaning of the slur to the Indigenous community.

"At the time this game appeared so fast.

"I'm so sorry that I used that word. I made him feel little."

Leniu said growing up with a Samoan background in Western Sydney, it was common among his family and friends to use those slurs among each other in a light-hearted way.

"All those types of words are used in our language and how we speak to each other," he said.

It was pointed out that Leniu was in his early teens when the same slur was directed at Indigenous AFL star Adam Goodes in 2013, and argued that Leniu would have been unaware of the slur used in the rival football code.

NRL counsel Lachlan Gyles argued for an eight-game suspension, while Leniu's lawyer said a four-week suspension would be sufficient in light of Leniu's guilty plea, remorse and willingness to appear in front of the panel in person.

James McLeod cited the four-game ban handed to the Warriors' Marcelo Montoya for a homophobic slur aimed at Cowboys winger Kyle Feldt in 2022, but the comparisons were rejected, with the panel reasoning that this case had affected Mam and his family on a more personal level.

Leniu's lawyers argued this case is a "turning point in the use of language in this sport".

"There is no room for racism in this game and I'm glad [Mam] brought it up," Leniu said.

The 23-year-old on Thursday apologised to Mam in a Roosters statement and pleaded guilty to the contrary conduct charge levelled at him by the NRL.

Leniu said he offered to fly to Brisbane to apologise to Mam in person, but the Broncos five-eighth did not want to meet with him, although the offer remains open.

Leniu will be eligible to play again in round 10 in the Roosters match with the Warriors.

The NRL's Indigenous player wellbeing and education manager, Dean Widders, was also at the hearing.

Widders was the victim the last time a player was banned for on-field racism, when then-Souths captain Bryan Fletcher directed a slur at Widders while he was playing for the Eels.

Paul Gallen was the last NRL player cited for racial abuse on the field, receiving a $10,000 fine over comments aimed at St George Illawarra's Mickey Paea in 2009.

"It hurts when you hear this stuff," Widders said on NITV's Over The Black Dot last week.

"It breaks you down, it tears you apart emotionally."

NRL great Johnathan Thurston said on Channel Nine the NRL should "show some leadership" and "throw the book at" Leniu.

There were calls for Leniu to be banned for half the season, with Indigenous All Stars captain Latrell Mitchell responding with "and some" when veteran commentator Andrew Voss suggested a 12-week suspension.

On the ABC's Offsiders last weekend, former representative back rower Ryan Hoffman said the apology was "too little, too late" after Leniu "doubled down" in the immediate aftermath.

"Until it came out there was no get-out clause for him, and now he's saying sorry," Hoffman said.

"[Leniu should be suspended for] half the season. This is an NRL moment, this cannot be tolerated in our game."