Deadline reports that the CBS drama's writing team assembled last week to begin working on a seventh season, but are still unsure if Gibson will reprise his role as Aaron 'Hotch' Hotchner.
Talks between the actor and CBS are said to have stalled, though producers are apparently still keen for him to return.
Gibson previously insisted that he is "hoping" to remain part of the Criminal Minds cast.
"I'm planning on being on the show, but we're still talking," he said. "I certainly don't feel like it's time to turn off the lights or anything like that."
The sixth season of Criminal Minds saw both A.J. Cook (Jennifer 'JJ' Jareau) and Paget Brewster (Emily Prentiss) axed from the show. Cook returned full-time beginning with the season finale, while Brewster has been confirmed to reappear in the show's seventh run.
Meanwhile, recent cast addition Rachel Nichols (Ashley Seaver) will not return as a series regular. Criminal Minds showrunner Erica Messer previously claimed that the axing "wasn't an easy decision", while Nichols herself described her exit as a "heartbreaker".
The seventh season of Criminal Minds will air on Wednesdays at 9/8c on CBS in the fall.