Now they play the New York Yankees in Game 1 of the World Series tonight at Yankee Stadium.
"We're excited, but we're going to be ready," Marlins manager Jack McKeon said. "These guys worked hard all season. They've had a lot of fun. And they're looking to have a little more fun over the next 10 days."
Look at the Marlins' lineup and you will see just two regulars 30 or older: catcher Ivan Rodriguez, 31, and leftfielder Jeff Conine, 37.
Whatever.
The Marlins have proved that experience can sometimes be overrated.
"I think when we went through a series with the Phillies, the Braves, the Giants and the Cubs that a lot of these guys grew up," McKeon said. "They had to survive a lot of pressure. I can really see them mature over the last few weeks. I can see the attitude difference. I think because of the experience we had in the last 10 to 12 days of the season and into the playoffs has really helped these guys mature quickly."
Those young guys have come up big over and over. Rightfielder Miguel Cabrera, 20, hit .333 with three homers and six RBIs against the Cubs, and .318 with three homers and nine RBIs overall in the postseason. In four postseason games, including three starts, Beckett, 23, is 1-1 with a 2.73 ERA. During the regular season, Dontrelle Willis, 21, went 14-6 with a 3.30 ERA.
"You know the thing I like about [Cabrera] is the same thing with Willis," McKeon said. "They're big-game players. All throughout the playoffs and the fight through the wild card, he's stepped and come up with big-game hits. He's quite a ballplayer."
McKeon, 72, has been cool and relaxed throughout the playoffs. He said yesterday that he feels no pressure. He is having the time of his life. He calls this the great moment of his baseball career.
It's easy to see why. A replacement in May, McKeon has turned the Marlins from a 19-29 team headed nowhere into a team that had the best record in baseball since the end of May.
It helps to be surrounded by good, young players.
"It starts in the clubhouse," Beckett said. "Everybody believes in one another. We believe in one another. Jack believes in us. There's not anybody on our team that - you go down the roster - will say, 'I don't believe in them.' You can say a lot about camaraderie and everything like that in the clubhouse. We're friends. And that helps.
"I was told by a coach before I signed on to play pro baseball, 'Don't go to make friends.' But I did, and I made a team full of friends."
McKeon echoed that sentiment.
"It's a tremendous thrill to be sitting here, but it's more of a thrill to say I'm the manager of this great Marlins team," he said. "These are the best young guys I've ever had anything to do with. I've never had a team that I've enjoyed more. A team that was more unselfish, more dedicated, more fun than these guys right here. I think that's the reason we're all in Yankee Stadium."
Contact staff writer Todd Zolecki at 215-854-4874 or tzolecki@phillynews.com.