Guillen was fired after only one year with the team, undone by too many losses and one too many ill-advised remarks.
A promising season began to derail in April with his laudatory comments about Cuba's former leader. Six months later, the episode was a factor in the decision to fire Guillen, Marlins officials said.
"Let's face it. It was not a positive for the team; it was not a positive for Ozzie," president of baseball operations Larry Beinfest said. "It was a disappointment, no doubt about it."
A lousy team didn't help, either. The Marlins took high hopes into their new ballpark following an off-season spending spree but finished last in the NL East at 69-93, their worst record since 1999.
Miami's next manager will be the fifth for owner Jeffrey Loria since early 2010. The latest change comes even though Marlins still owe Guillen $7.5 million for the three years remaining on his contract.
"We all felt we had a pretty good ballclub coming out of spring training, and we just didn't play well," Beinfest said. "We all share in this. This is not a fun day for me, certainly not for Ozzie or Jeffrey or anybody involved. This is an organizational failure. But we felt like we needed to make this change so we could move forward."
There had speculation that Beinfest's job might also be in jeopardy, but he'll continue in his current role. The search for a new manager has just begun, he said.
"We could definitely use some stability in the dugout," said Beinfest, who has been with the Marlins since Loria bought the team in 2002. "We're looking for a winner. At times we've done a better job of identifying that individual. Other times we haven't. We're going to try to find the right guy this time."
On Twitter, Guillen said the firing left him with "my head held up high, real high."
"To the fans that support me and for those who are happy as well my love and respect to you," Guillen tweeted. "In life there are worse things and I have experienced them. I have lived through bad moments and I will get through this with support."
In spring training, Guillen touted his team as well balanced and ready to win. But a dismal June took the Marlins out of contention for good, and management dismantled the roster in July.
The season went sour from the start. Guillen's comments praising Castro in a magazine interview angered Cuban Americans, who make up a large segment of the Marlins' fan base. The Venezuelan manager apologized repeatedly at a news conference for his remarks, then began serving a five-game suspension only five games into his stay with the team.
"That was a very, very hard situation for me and the people around me," Guillen said in September. "It was maybe the worst thing I ever did."
Marlins officials believe the damage was lasting. They blame disappointing attendance at the new ballpark in part over lingering fan resentment about the Castro comments.
The decision to fire Guillen came on the eve of the World Series, nearly three weeks after the Marlins' final game, following a lengthy assessment of what went wrong this year.
"Everybody wanted to take a step back," Beinfest said. "It was really an organizational decision."
Guillen was returning Tuesday from a vacation in Spain and was informed of his dismissal by phone by Beinfest in a brief conversation.
Guillen left the Chicago White Sox a year ago after eight seasons. Some 24 hours later he sealed a four-year deal with the Marlins, where he was a third-base coach for the 2003 World Series championship team.
"I feel like I'm back home," he said at the time.
Loria traded two minor league players to obtain Guillen and gave him a team-record $10 million, four-year deal. But by June, the Marlins had fallen below .500 for good.
Despite the frustrations of losing, the talkative, opinionated, profane Guillen kept his cool for the most part, and he repeatedly accepted responsibility for the team's performance. Mindful of speculation his job might be in jeopardy, he said two weeks before the end of the season he was glad he rented a house in Miami rather than buying when he took the job.
"With the job I did this year, do you think I deserve to be back here?" Guillen said on the final day of the season. "Of course not. But I'm not the only one. ... Let's start from the top. The front office failed, Ozzie failed, the coaching staff failed, the players failed, everybody failed."
In December, the Marlins signed All-Stars Jose Reyes, Mark Buehrle and Heath Bell to contracts worth a combined $191 million. But Bell was a bust as the closer, and the Marlins were plagued by poor hitting, especially in the clutch.
Bell was traded last week to Arizona.
In the Marlins' 20 seasons they have reached the post-season only twice, as wild-card teams in 1997 and 2003. Both times they won the World Series.
Under Loria they have usually been among baseball's thriftiest teams. With attendance and revenue falling short of projections this year, the spending binge of last off-season ago is unlikely to be repeated.
"We need to spend some time redefining ourselves in conjunction with a new manager," Beinfest said. "I can't tell you exactly what the Marlin way is today."