Prolific Souths winger Johnston is only two tries from passing Ken Irvine's mark of 212 career four-pointers and could enter rarefied air during Friday's clash with rivals the Sydney Roosters at Allianz Stadium.
Stadium security is expected to be increased for the round two clash and fans risk $5,500 fines should they breach the field of play.
Souths coach Wayne Bennett intimated on the weekend that rushing the field would not be in the spirit of rugby league, with Johnston's teammates flagging their own concerns on Tuesday.
"We want to keep the players and even the fans as safe as possible," said Souths captain Cameron Murray.
"It'll be a bit chaotic if people run on if AJ breaks the record. I'll back what coach said. It's not something that I want to see.
"As much as I can empathise with the fans wanting to run on and celebrate, I think it goes against the spirit of the game. It's not really us."
The NRL's equal-shortest player at 170cm, Souths fullback Gray will be seeking out giant winger Campbell Graham if fans begin to close in.
"I was talking to 'Stretch' this morning, actually, and I asked him to carry me in the air so I don't get squashed under everyone," Gray said with a smile.
"Obviously the security have a job to do. It could get dangerous."
AFL supporters memorably stormed the SCG pitch in early 2022 when Sydney key forward Lance Franklin became only the sixth player to kick 1000 career goals.
On that occasion, the game against Geelong needed to be delayed by more than half an hour so players and fans could return to their positions.
Murray said Johnston would not want his milestone celebrated in that way.
"We're separate to the AFL," Murray said.
"I think you have to look at what happened there, I think it took them an hour or something to get everyone off the field. I don't think all the players, AJ included, would be wanting that.
"It'll be an incredible moment if it happens, we'll celebrate it our way, and we'll make sure we do the milestone justice."
Anticipation of Johnston's milestone has been brewing for years, particularly since the 31-year-old returned from the long-term Achilles tendon injury he suffered in 2024.
"It'll be nice when he gets the monkey off the back but I don't think it's affecting him too much," Gray said.
