Jennings, who had already been informed that he will not return as manager, but he has been asked to go back into the front office as general manager, club president David Samson said on Tuesday.
The Marlins have already started the interviewing process with at least three potential managerial candidates. Phillies bench coach Larry Bowa was scheduled to talk with club officials on Monday. Previously, Manny Acta and Bo Porter discussed the job.
The manager search could take a while, as numerous choices are expected to be considered, with some possibilities currently with postseason clubs.
Miami is targeting candidates who have already managed in the big leagues.
Miami's coaches, meanwhile, have been informed they may explore other possibilities.
The Marlins staff includes, Mike Goff (bench), Perry Hill (infield/first base), Frank Menechino (hitting), Chuck Hernandez (pitching), Reid Cornelius (bullpen), Lenny Harris (third base), Brett Butler (outfield), Pat Shine (administrative coach and video replay coordinator), and Jeff Urgelles (bullpen coordinator).
Joe Frisaro is a reporter for MLB.com. He writes a blog, called The Fish Pond. Follow him on Twitter @JoeFrisaro and listen to his podcast. This story was not subject to the approval of Major League Baseball or its clubs.