NRL CEO Andrew Abdo says players will not be mandated to have a COVID-19 vaccine but warned unvaccinated players would be subject to more stringent protocols.

On the same day the AFL mandated its players to be vaccinated by mid-February, Abdo took a slightly different approach.

The NRL has been grappling with mandatory vaccinations since the resumption of the 2020 season when several high-profile players including Bryce Cartwright, Josh Papalii and Joseph Tapine expressed reluctance to receive the flu shot.

Despite many businesses and rival codes mandating employees to receive a COVID-19 vaccine, Abdo said the NRL would leave it up to the players.

"Clearly we need to make sure we have continuity to the competition, and we are creating a safe working environment," he told Channel 7.

"We are busy working on the protocols for the players who are vaccinated and the players that are not vaccinated. Hopefully we are talking about a very small group of players.

"They will have, I'd imagine, some pretty rigorous requirements around what they will be able to do in order to train and play.

"Of course this might be taken out of our hands by health orders or by airlines, so there will be repercussions for those that don't choose to be vaccinated but it's not our approach as a governing body to mandate it.

"Between now and the end of the off-season we will have a very clear set of guidelines for how the clubs and players can get back to training safely for those who are vaccinated and those who aren't yet vaccinated."

Abdo claimed some clubs had close to 90 per cent of players and staff vaccinated with the governing body's own staff up to 98 per cent.

Meanwhile, Abdo said the potential introduction of an 18th team could see the NRL introduce a conference system.

The Redcliffe-based Dolphins, who unveiled Wayne Bennett as their coach on Thursday, will become the 17th NRL franchise in the 2023 season.

While he refused to speculate when and where the 18th club would come from, Abdo said the increase in teams would force the Australian Rugby League Commission to examine a conferencing system.

"You've got to begin with the end goal in mind," he said. "An 18th team gives us another game each round and the even number of teams allows for different configurations.

"We should look at the virtues and the pros and cons of a conference model. We suffer from a draw that is not symmetrical.

"Not every team is playing the other team home and away.

"The advantage of a conference model - and it doesn't have to be geographical - is you're able to provide equity in the draw which provides fans with clarity over who they'll play each season.

"You can focus in on local rivalries and a competition within a competition."