Fans of the "Expendables" franchise were shocked to learn Friday that star and writer of the series, Sylvester Stallone, has reportedly walked away from any future work on the films. First reported by Deadline Hollywood, Stallone was to be heavily involved in a fourth installment of the blockbuster movie saga, but multiple disagreements with producer Avi Lerner led to the split.

'Expendables 4' would have been biggest payday of Stallone's career

In a career filled with blockbuster action movies like the "Rambo" and "Rocky" franchises, Stallone has typically received less up-front per Film, compared to other stars of his caliber.

Instead, he will reportedly negotiate with studios to allow himself writing and directing opportunities, picking up a bigger payout in bonuses after the movie is released.

According to Deadline sources, Stallone was to take home over $20 million in advance of shooting "Expendables 4," and would have been in line to pull in another several million dollars in bonuses as a producer. This would have made the movie not only the biggest pay day of Stallone's career, but could have landed the actor as one of Hollywood's highest paid stars.

Sequel was last talked about in December

Back in December 2016, Stallone took to his official Facebook page to update fans on the "Expendables" sequel and teased a possible connection to another film from earlier in his career: "Cliffhanger."

In the short video post (below), Stallone can be seen discussing his excitement for the anticipated "Expendables 4" and briefly mentions the 1993 action hit.

After the video's release, fans and some movie bloggers began to speculate that the location and theme of the sequel may somehow relate to the older film, especially since a remake of "Cliffhanger" has been in the works for a number of years. Unfortunately, fans may never know if those theories are true, if Stallone has left the series for good.

An unnamed source close to the "Expendables" project cites a number of major disagreements between Stallone and producer/studio head Avi Lerner to be at the heart of the rift, telling Deadline, "We agreed on 95% of things, but there are certain things in production we don’t agree on."

The "certain things" being referred to seem to include everything from visual elements, major plot points, the script, and even a new director.

(Speculation continues that Stallone may have wanted to delay production in order to get "Cliffhanger" director, Renny Harlin.)

If "Expendables 4" is able to move ahead, actors Jason Statham and Dolph Lundgren had been previously confirmed to reprise their roles from the prior movies. A television adaptation of the movie franchise has been announced by Fox, with Stallone and Lerner producing. There is no word yet on how Stallone's exit from the films may affect the television series.