Damon has played secret agent Jason Bourne in three films, but sparked rumours of a departure from the franchise when director Paul Greengrass quit and the actor insisted he would not return to the role unless his pal was in charge.
Michael Clayton moviemaker Tony Gilroy, who wrote the screenplay for the three Bourne movies, has been hired to take over from Greengrass and he has now confirmed Damon will not be a part of new movie The Bourne Legacy.
And he's revealed the film will not feature the title character at all.
He tells Hollywood Elsewhere, "This is not a reboot or a recast or a prequel. No one's replacing Matt Damon. There will be a whole new hero, a whole new chapter... this is a stand-alone project."
But Gilroy insists Damon has the option to return to the franchise in the future.
He adds, "The easiest way to think of it is an expansion or a reveal. Jason Bourne will not be in this film, but he's very much alive. What happened in the first three films is the trigger for what happens. I'm building a legend and an environment and a wider conspiracy... the world we're making enhances and advances and invites Jason Bourne's return (in the future)."