The team planned to open their locker room to the media Monday morning. Marinelli was to be available for comment at a news conference.
Millen was fired as team president three months ago, but the players he left behind coupled with the former Tampa Bay players Marinelli wanted created the perfect storm for a historic season of futility.
Fans and reporters cut Marinelli some slack during in his first year, when he went 3-13, because of the Millen-created mess he inherited. Hopes rose when Detroit was 6-2 midway through last year but were quickly dashed when the team finished 7-9.
The Lions fired offensive coordinator Mike Martz after the 2007 season but retained Marinelli's son-in-law to lead the defense.
That led to more scrutiny and exchange with a columnist that made Marinelli a martyr of sorts.
Marinelli didn't answer the question during his news conference, but lashed out the next day with anger he hid after his string of losses.
"Anytime you attack my daughter, I've got a problem with that," Marinelli bristled.
Marinelli kept his composure for the most part in public and steadfastly stood by his one-snap-at-a-time mantra and choice of work ethic over talent.
"You don't look for wishy-washy people, who give in when the press thinks you should do this or somebody is complaining about practicing in pads," Marinelli said in a 2007 interview with The Associated Press. "I have a belief. I state it very clearly. And I live it."
The Vietnam veteran said he would never quit, saying he was insulted when a reporter asked about the option.
Marinelli waited for three decades to be a head coach. He finally got his chance with a team in the middle of one of the worst stretches of futility in NFL history.
His relentless ways helped him make a deliberate rise through life and the coaching ranks.
Marinelli's college career — starting at Utah in 1968 and ending at California Lutheran in 1972 — was interrupted by a one-year tour in Vietnam. He knew some would be interested to hear his perspective of how serving in the war shaped his life and career, but he politely declined.
His career started in 1973 as an assistant coach at his alma mater, Rosemead High School, where the football field is named after him.
Marinelli went on to work on the staffs at Utah State, California, Arizona State and Southern California before Tony Dungy gave him a shot in 1996 to work in the NFL as defensive line coach in Tampa Bay.
A decade later, Detroit was desperately looking for a coach to turn around the laughingstock of the league. Millen hired Marinelli after an extensive search.
Now, the Lions are looking for another coach to take on the monumental task of turning them into a winner.