Johnston will return from an achilles tendon rupture against an undermanned Penrith at Accor Stadium on Thursday night, playing his first NRL game since going down injured last August.
His return comes as a bittersweet moment for Souths, with Bennett also revealing centre Campbell Graham will miss close to a month of football with a calf muscle tear.
Johnston and Graham spent periods of injury rehabilitation together last year, with Campbell missing all of 2024 following sternum surgery.
But while he is set for another frustrating stint on the sideline, the next little period looms as crucial for Johnston.
The flyer is off-contract at the end of this year, and requires 18 more tries to break Irvine's long-standing all-time league record of 212 tries.
Talks are yet to begin over Johnston's future, but Bennett said that would come with him keen to keep the winger at the club.
"He's been a lifelong player here and is closing in on being the leading try-scorer in the game," Bennett said.
"The club would like to see him finish his career here.
"We'll talk to him ... We want him to stay, but they've got to want to stay as well and be happy with the deal.
"Because sometimes you can't plan as much as you want to. So that's all to be sorted out."
The 30-year-old came close to being let go by Souths during Bennett's last stint in 2020, before he was eventually re-signed amid a fan petition to keep him.
Bennett said he would like to see Johnston break Irvine's record while wearing a Rabbitohs jersey, after he debuted at the club in 2014.
"We'd like that," Bennett said.
"He's in great shape and still enjoying his football and still very capable.
"We'll get Latrell (Mitchell) back (next week) and Latrell will give him some opportunities.
"He was a great player Ken Irvine, I remember him playing. I'm happy for AJ, but it's all got to be done. He's close though."
Bennett was also confident Johnston had not lost any of his pace on return from the injury, as is sometimes the case after achilles ruptures.
Any loss in speed would be a serious blow for Johnston, who relies heavily on his pace out wide rather than size for yardage like most other modern-day wingers.
"There's a lot of data. These players have trained for so long with GPS. So we know what his top speed is and what it has been in the past," Bennett said.
"And I think he's pretty much on the money at the moment.
"The way they rehab, it's incredible to watch him go through the process with the staff here to get him back to that pace and make sure that they don't recur again."
10°C