The Marlins on Tuesday dismissed Guillen after the 48-year-old led Miami to a disappointing 69-93 record and last-place finish in the National League East.
"After careful consideration following the disappointment of the 2012 season, we decided to dismiss Ozzie," president of baseball operations Larry Beinfest said. "Our managerial search begins immediately, and our hope is that a new manager, along with roster improvements, will restore a winning culture."
Guillen is still owed $7.5 million for the three years remaining on his contract, which was the richest managerial deal in team history. The club is renewing the contracts of Reid Cornelius, the club's 2012 bullpen coach, and Joey Espada, who served as Guillen's third-base coach, but the rest of the staff will not return. Cornelius' and Espada's roles for next season have yet to be defined.
Guillen addressed his dismissal later in the day on his Twitter feed, @OzzieGuillen.
"In life there are [worse] things and I have [experienced] them," Guillen said. "I have lived through bad moments and I will get through this with support. [...] Better things will come or [worse] things but they will come. Thanks a lot for the support in this difficult time but not the worst. [...] [I'm] fine with the people that I love with my head held up high real high."
Beinfest said he informed Guillen of his dismissal over the phone, a conversation Beinfest called brief and professional.
The move comes a little more than a year after Guillen was introduced as Marlins manager, a new face for an organization embarking on many changes. The club moved into new Marlins Park, changed its name and colors, and expected to contend for a playoff spot after an offseason spending spree of $191 million landed them shortstop Jose Reyes, left-hander Mark Buehrle and closer Heath Bell -- who last week was traded to the D-backs.
The Marlins hoped Guillen, who came to Miami after eight seasons in Chicago, would become a powerful face and voice for the organization.
"We knew Ozzie when he was a coach here, but you never really know someone until you live with them in the manager spot," Beinfest said. "Ozzie's Ozzie. That's the way he is, and that's what made him a Major League manager over the years."
Ozzie was Ozzie almost immediately, making comments in April praising Fidel Castro, the former Cuban leader, in a magazine interview, resulting in a five-game suspension.
Beinfest said Guillen's Castro comments were only part of the equation the Marlins used when deciding to move on.
"I don't think it's any one thing. I think it's cumulative. It's a complete evaluation, and we wanted to move forward," Beinfest said. "Look, there was nothing positive about that. It was a black eye for Ozzie, for the organization and we moved on it. We tried to move on from it and we recognized the magnitude of it. I would say that if we were going to say Ozzie got fired because of the Castro thing, that wouldn't be fair. Ozzie got fired because of an evaluation over a number of things."
Aside from a 21-8 May, nothing much went right for the Marlins. They were 8-18 in June and became a seller as the July 31 non-waiver Trade Deadline neared. Dealt to the Dodgers was Hanley Ramirez, who shifted from shortstop to third base upon Reyes' arrival. Infielder Omar Infante, right-hander Anibal Sanchez, first baseman Gaby Sanchez and relievers Randy Choate and Edward Mujica also were traded.
The Marlins continued to flounder with a less competitive roster, for which Beinfest said he and the front office take part of the blame. Beinfest admitted 2012 was like two seasons, which is why the Marlins waited nearly three weeks after the regular season ended before making a decision in an attempt to step back and evaluate Guillen's season.
Now the Marlins are searching for their fifth manager in the past three seasons after dismissing Guillen, who has a career managerial record of 747-710 in nine years, including a World Series championship with the White Sox in 2005.
Beinfest said he didn't think the Marlins' recent string of managers would affect the club's ability to find a replacement. But he admitted the Marlins would like to bring stability to the position.
"We've got a lot of stability in the front office, a lot of stability in ownership and I think stability in the dugout could be a benefit to our players," Beinfest said. "Ideally, yes, it would be outstanding to have a manager down there for a number of years and winning."
Beinfest said the Marlins have yet to start a search for Guillen's replacement, but are open to hiring a manager without experience, similar to what the Cardinals and White Sox did last season with Mike Matheny and Robin Ventura, respectively. Blue Jays Class A manager Mike Redmond is a strong candidate, and Dodgers third-base coach Tim Wallach and Reds pitching coach Bryan Price are also expected to be in the mix.
Beinfest also said he wants a manager who can take the club's current talent, communicate with the front office and ownership and create a winning atmosphere.
"For a number of years here, even after we won the World Series, we found ways to overcome challenges on the field, and I think we've gotten away from that a bit," Beinfest said. "We need to get back to that. We don't need to necessarily talk about winning divisions or winning Wild Cards; we need to win, period. And we need to have that culture here, and that's missing."
Cash Kruth is a reporter for MLB.com. Follow him on Twitter at @cashkruth. MLB.com reporter Joe Frisaro contributed to this report. This story was not subject to the approval of Major League Baseball or its clubs.