Smith is yet to confirm if he will return for a 19th season next year, with Melbourne teammates still in the dark on whether he will play on.

Re-signed on a new deal at the start of last season, Smith's contract for 2020 is in the form of an option in his favour - meaning he can choose whether or not to activate it.

Widely regarded as one the finest players ever to lace up a boot and an Immortal-in-waiting, Smith passed the 400-game milestone this year and will also finish his career as the most capped State of Origin player.

But the 36-year-old has also been the subject of increased scrutiny in 2019, prompting coach Craig Bellamy to warn the criticism could have worn him down last month.

And Meninga, who is a close confidant of Smith through their time as captain and coach of Queensland and the Kangaroos, said he could understand if he left the NRL.

"I would be thinking the same thing if I was in his shoes," Meninga told AAP.

"I think he's got the ability to play another year and I think Melbourne need him to play another year from a transition point of view.

"But I could understand if he wants to quit too because of all the negativity.

"(If I'm him) I'm thinking 'I am sick of this. What have I done wrong? I've been a great ambassador for rugby league. I've been a great player, I do everything right.

"I've been up there for long periods of time and people want to keep knocking me down. Why?'"

Meninga believed the criticism was nothing new for Smith, but said it had reached new levels in 2019.

Smith's style of play has been heavily scrutinised, and he was forced to deny claims he'd pulled on Canberra winger Bailey Simmonsen's ears in a tackle in August.

There have been continual jibes for many years over a supposed influence on referees.

Smith, who did not attend this year's Dally M or RLPA awards, is also believed to have been angered by questions asked over an expensive ring given to his wife Barbara from the NRL to celebrate the 400-game milestone.

"It's Australian tall poppy syndrome," Meninga said of the criticism Smith cops.

"We build them up and because he has been up there for so long and been so successful someone feels it's their job to bring them down.

"I don't understand why athletes like Cameron Smith don't get lauded and acknowledged by everyone. It's damn hard to stay at the top.

"And he has done that over 17 years and people want to knock him down. I think it's stupid. Very un-Australian."

Australian Associated Press