In the process, the club completely reversed how it conducts business, as it attracted several strong personalities. Miami added characters like fun-loving Heath Bell, energetic Jose Reyes, steady Mark Buehrle and sometimes combative Carlos Zambrano.
The newcomers are blending into a roster that had pretty much remained low-key and free of distractions.
To keep peace and harmony in their now colorful clubhouse, the retooled Marlins hired one of the most outspoken managers the game has seen in years. Ozzie Guillen, who tells it like he sees it, is considered crazy enough to keep Miami sane.
"In the past, the Marlins weren't spending any money, and people said the Marlins don't care about the team," Guillen said. "[They'd say] 'The Marlins have a bad ballclub, and they play in the worst ballpark in baseball.' Now, we changed that thing around, and we're still getting criticized. 'Where did they get the money? Why did they get the ballpark? Why did this guy sign?'
"Now, they don't know what to say. Now, they say, 'They're all crazy people. Zambrano is there. Guillen is there. Bell is there. Reyes is there and Hanley [Ramirez] is there. It's a crazy team.' We can't make everybody happy. But I'm very happy with what we've got. We've got young talent. I like that. You can mold them right."
For all the bluster and bluntness you get from Guillen, the Marlins believe they got the right man at the right time.
He's been a winner. In 2005, Guillen guided the White Sox to their first World Series title since 1917. He also became the first Latino manager to win the title.
As a player, Guillen won the American League Rookie of the Year Award in 1985, and he played 16 seasons. He also won the AL Manager of the Year Award with Chicago in '05.
With Miami's strong Latin influence, the Venezuelan-raised Guillen is a natural fit.
For two years, the Marlins monitored Guillen's status in Chicago. When it was obvious his tenure with the White Sox was coming to an end, owner Jeffrey Loria got involved, eventually hiring Guillen in September.
Money wasn't an obstacle, as Guillen signed for $10 million over four years.
No stranger to the Marlins, Guillen was the team's third-base coach in 2002-03, before he took over the White Sox in 2004. By the end of 2011, it was a time for a change, for the manager and Chicago.
The Marlins officially announced the hiring of Guillen on the final day of the 2011 season, which also marked the finale of the franchise as the Florida Marlins, playing in Sun Life Stadium.
Now the Miami Marlins are set to play their first season in a comfortable retractable-roof ballpark, which has a capacity of 37,000.
Guillen's straight-shooting style is the way he connects with his players. There is a flare in his delivery and approach that is in stark contrast to previous managers like Jack McKeon, Edwin Rodriguez and Fredi Gonzalez.
"I think it will be a change," Marlins president of baseball operations Larry Beinfest said. "I think it will be a fun, refreshing change. The thing about Ozzie is, when you talk to players who played for him, they generally really like playing for him. I think that's huge.
"You have to have fun. There is enough stress and pressure in this game. To get a guy that you like playing for, he's fun to be around. He's protective of his players. He tells players the truth. That's really what guys want. I think it's a big change from what we've had."
Dealing with elite players with big egos is nothing new for Guillen, who has managed the likes of A.J. Pierzynski, Omar Vizquel, Ken Griffey Jr., Jim Thome and Manny Ramirez.
"I've managed [future] Hall of Famers, and they were good with me," Guillen said.
Guillen asks for three things from his players: communication, respect and loyalty.
"Make sure that when you are talking to them, you're telling the truth," Guillen said. "It's going to come from me, good or bad. When I say a good thing about you, I mean it. When I say a bad thing about you, I really mean it."
Guillen welcomes the task of connecting with his new team, and how he deals with Ramirez's mood swings, and his transition to third base, will be closely watched.
"This ballclub is not about 24 guys, 22 guys, it's about 25 guys," Guillen said. "I didn't expect Hanley to be very happy [about changing positions] when that thing happened. But I expect Hanley to come to the ballpark with a smile on his face, and try to put his mind on having MVP numbers and be the happiest man he can be, and to help us win games. That's all I expect from him. I don't expect him to be a Gold Glover. I expect him to go out there and show his teammates, show baseball and show himself. He doesn't have to show me. He has to show himself how good he is, and how important it can be for him this year. I expect him to be fine."
If the first few days of Spring Training mean anything, Ramirez and Guillen will get along just fine.
"He's a good guy," Ramirez said of his new manager. "You've got to show him you come to play every day, and hustle every day. That's what he likes for his players to do. That's all. Every manager wants that. You can go 0-for-4, but if he sees you give everything you've got, he's going to be cool with it."
Guillen's presence certainly factored into Miami signing Buehrle and trading for Zambrano.
With Guillen, Buehrle was the White Sox ace for years. The veteran left-hander signed a four-year, $58 million deal with the Marlins, in part because of Guillen.
"You don't know what's coming," Buehrle said. "I think you guys [the media] are going to like him a lot. He goes on and starts ranting. You don't know what he's going to say or what he's going to do.
"It's kind of the unknown, but at the same time, he's going to tell you you stink if you stink. He will tell you the reason you're not playing or why they're going to play you more. He will tell you the way it is."
How Guillen deals with Zambrano is theater waiting to happen. The two Venezuelan natives are close friends, and Guillen was a driving force in the Marlins trading Chris Volstad to the Cubs for the volatile veteran.
But can the two friends co-exist? Guillen laughs when he says people in Venezuela are placing bets on when he will have a confrontation with Zambrano.
"Carlos is a different person than people think he is," Guillen said. "Carlos is a different human being with the uniform on and with the uniform off. Do I expect Carlos to be upset? Yes, please be upset. I don't want to lose a game and to see people who seem like they don't care. But is Carlos going to hit one of my players? No."
A year ago, Zambrano had a nightmarish outing against Atlanta, and he showed his frustration by throwing at Chipper Jones, leading to an ejection.
Guillen said he will not tolerate Zambrano throwing at a hitter without his approval.
"I know Carlos will get upset," Guillen said. "If he wants to throw a Gatorade cooler, please do. But don't hurt anybody. One thing Carlos can't do, if Carlos throws [a pitch] at somebody without my permission, then we're going to have problems. I don't like people throwing at people, because somebody can get hurt.
"If you get upset because you [stunk], pitch better. Believe me. I have people in Venezuela betting to see when will be the first time me and Carlos will have a fight."
Another no-no in Guillen's book is badmouthing a teammate behind his back.
"If you're going to talk about another teammate, be ready for the biggest fight," the no-nonsense manager said. "I will fight you. You will kick my butt. I'm old and out of shape. But I will fight."
Zambrano is not looking for an altercation with his manager, he's looking to prove that Guillen was right in having faith in him.
"I'm very thankful that Ozzie pushed to bring me here to the Marlins," Zambrano said. "He's a manager that is dynamic. I am a big supporter of his mentality as a manager and I am very happy to have the opportunity to play for him on this team.
"We were both in Chicago, and he was always giving me good advice. Every time we would see each other, he always had something good to say to me. He's a mentor to me. He's someone that when you play hard for him and do things the right way, he will be behind you. He's someone who knows a lot about baseball, and those are people who should be respected. You need to listen to people like that."
Around Guillen, you can't help but take notice of what he's saying, which is a big reason he was coveted to elevate the Marlins into serious contenders.