Fifita has publicly threatened to leave the NRL after being snubbed for Kangaroos duty despite being the form prop in the game.

The 27-year-old was overlooked due to a series of off-field issues including his public support for one punch killer Kieran Loveridge.

Fifita has been linked to the English Super League and French rugby.

Grant said Fifita did not have to quit the NRL.

"He doesn't need to do that. I don't know why there'd be any contemplation of that," he said.

"What Andrew needs to do is what he's been asked to do, which is behave like an adult.

"Andrew's a great player, we want him in our game, but you've got to be a certain individual - particularly this rankle is all about selection for the Kangaroos and not being available for selection.

"We're very purposefully making the Kangaroos the elite rugby league team in Australia, it's a global team and we're going to get not the best players but the best men.

"That's what Mal Meninga's 100 per cent committed to and what we as a game are 100 per cent committed to and Andrew can be that.

"Andrew just needs to improve, frankly, off the field - it's as simple as that.

"(But) I'd be really surprised if he doesn't know this. I'm not in the day-to-day so I don't know what's gone on but it's impossible to believe that Andrew, through his club or coach or Mal Meninga or the NRL, doesn't clearly know what's expected of him.

"The game made Andrew unavailable for the Kangaroos and that's really disappointing for everyone... but just look at this Kangaroos side and have a look at the stories of redemption in this Kangaroos side. Andrew can be a Kangaroo."