Russell has never been one to mince his words but his latest comments are said to have his close friends concerned, particularly about his threats of going underground.
Since rocketing to the top of Hollywood's A-list after his Oscar win for playing muscular Maximus in Gladiator, Rusty has had a lot on his plate, both professionally and personally.
Most heavy was his 2018 divorce from Danielle Spencer, the mother of their sons Charles, 19, and Tennyson, 17.
Russell's admission about possibly hanging up his hat after 40 years in showbiz comes after his most recent film, this year's The Pope's Exorcist, bombed at the box office.
Its failure comes on the back of his 2022 directorial effort, the thriller Poker Face, copping flak for its weak plot.
Despite Rusty's burly exterior, friends admit that, deep down, he is quite a sensitive soul and is struggling to keep up the same standards and pace he once maintained, especially when it comes to his fitness.
It's no secret that the star has a history of yo-yo dieting.
In particular, he reportedly gained a whopping 35kg to play Fox News CEO Roger Ailes in the 2019 miniseries The Loudest Voice.
Friends say that the strain Russell put his body through to transform for jobs over the years is finally taking a toll.
As rumours of a second marriage to his current partner, Britney Theriot, persist, the star is determined to loose weight for his big day.
Fitness fanatic Brit, 40, has been encouraging him to lead an active lifestyle, and the couple are often seen playing tennis and riding together.
Even with his lapse in confidence, when it comes to accepting his advancing years, Rusty is grateful to have a partner like Britney.
"She believes wholeheartedly in her man and his capabilities, so although she would support his decision to retire, she knows he has more to give," says a source.