The series starred Michael Chiklis as corrupt cop Vic Mackey and ran for seven seasons between 2002 and 2008.
"Michael Chiklis and I talk about [a film] at times," Ryan told Entertainment Weekly. "[But] I'm always reluctant to talk too much about it in the press because I wouldn't want to give fans false hope."
Ryan previously claimed that the project is "up in the air" but told EW that he is still "open" to the idea.
"If the right idea at the right time came through the Fox movie division, we'd be open to it," he insisted. "I'm sure there's a movie that could be made for a price that could made sense."
Since The Shield concluded, Ryan served as showrunner on the second season of Fox's Lie To Me and also created recently-axed cop drama The Chicago Code, while Michael Chiklis starred in ABC's No Ordinary Family and new CBS pilot Vince Uncensored.
During its run, The Shield won a Golden Globe for 'Best Drama Series' and Chiklis was awarded both a Golden Globe and an Emmy for his central performance.