The former South Sydney captain has checked into a rehabilitation facility to support his mental health having struggled to cope following his decision to call it quits on rugby league.

Inglis brought down the curtain on a decorated career last month but has reportedly battled alcohol issues, with concern for his welfare rising after he failed to turn up to work for the Rabbitohs.

It is understood the 32-year-old could be bracing for a months-long stint in rehabilitation rather than checking out in a matter of days or weeks.

Greenberg says he has been in contact with the Queensland and Australian Kangaroos great with NRL supremos working to strengthen programs to help players transition into life after football.

"The short answer is we can always do more," Greenberg said.

"I've been in constant contact with Greg and his club. In fact, I am pleased he has taken that step, it's an important step for him. Clearly he has had some difficulties, and I am glad he is getting the specialist support he needs.

"Mental health is an issue, not just for rugby league but for the broader community. We run a number of very important programs, and we have done over a long period of time.

"The most important thing we can continue to do is reduce the stigma, to take away the stigma. When someone puts their hand up and asks for help, that's a good thing.

"What Greg is doing at the moment is reaching out and asking for professional help. Let's remove the stigma and say that's a good thing. He has been open about some of his challenges with mental health.

"I have got to know Greg over a long period of time, it takes real bravery to admit some of your own failures. He'll get the help he needs.

"As a community and as a country, when talking about mental health, it's okay to put your hand up and ask for help. It's actually a sign of great strength."

The NRL has run a State of Mind program in recent years designed to start positive conversations, break down stigmas and encourage people to seek help for mental health problems.

Inglis was handed a role with the Rabbitohs' charity organisation, Souths Cares, and as both an indigenous mentor and club development coach following his decision to retire despite boasting a year to run on his contract.

Rabbitohs coach Wayne Bennett said Inglis was the happiest he'd seen since arriving at the club's Redfern headquarters after a game earlier this month.

But the premiership-winning fullback has since opted to undergo further treatment on his mental state having previously shared the news he had bravely checked into rehabilitation back in 2017.

Bennett has said "the best thing about Greg is that he is getting the support that he needs" but did not want to elaborate on the situation.

Greenberg is doing the rounds at all 16 NRL clubs and met with the Canberra Raiders' leadership group on Friday morning with player welfare high on the agenda.

It was a chance for Greenberg to address the code's forgettable off-season which was marred by off-field indiscretions, with the NRL boss "making sure I take the opportunity, when I'm looking through the whites of the eyes of the players, to make sure they understand their obligations".

Canberra's leadership group, led by co-captains Jarrod Croker and Josh Hodgson, were keen to delve into the game's effort's to help players adjust to life after the final siren.

Greenberg says the NRL is planning to introduce more programs to assist players in making the move from the regimented life of a footballer to a more normal lifestyle.

"We've got to do it across all parts of our playing group, and we've got to make sure we continue to invest in this part, but also making it really meaningful for players so it actually helps them transition," Greenberg said.

"A player's career is not the end, it's actually the start of the next journey, and we've got to change the language around that.

"There is a very strong leadership group here at the Raiders and it was a very good discussion."