Opening Day starters

• Josh Beckett – SP
• Luis Castillo – 2B
• Juan Encarnación – RF
• Álex González – SS
• Todd Hollandsworth – LF
• Derrek Lee – 1B
• Mike Lowell – 3B
• Juan Pierre – CF
• Iván Rodríguez – C ^[7]

Season standings

Game log

Postseason Game Log

Sluggish start

Jeff Torborg, the manager at the start of the season, led the team to a 16-22 start. Adding to that, their three top pitchers A. J. Burnett, Josh Beckett and Mark Redman, had each endured injuries that season, but Beckett and Redman were able to return to finish the rest of 2003. On May 11, Torborg was fired and replaced with Jack McKeon, a 72-year-old who began his major league managerial career in 1973 with the Kansas City Royals.

Midseason acquisitions

• Miguel Cabrera – 3B → called up from the AA Carolina Mudcats
• Jeff Conine – 1B → acquired from Baltimore in exchange for two minor league players.^[8]
• Dontrelle Willis – LHP → called up from the Mudcats.
• Ugueth Urbina – RHP → acquired from Texas in exchange for Adrián González and two other minor league players.^[9]
• Aaron Small (RHP) signed as a free agent.^[10]

Roster

Batting

Pitching

National League Division Series

The Marlins won the Division Series over the heavily favored defending National League champion San Francisco Giants. The series ended with a play at the plate with catcher Iván Rodríguez prevailing over Giants first baseman J. T. Snow. Coupled with a perfect throw from Conine and an amazing catch from Rodríguez, Snow was attempting to score by using a football type bulldozing move, but Rodríguez held on and the Marlins won, marking the first time that a post-season series ended with the potential tying run being thrown out at home plate.

NLCS

The 2003 National League Championship Series is arguably one of the most famous (or infamous) post-season series in MLB history. On one side, the Florida Marlins, the miracle who, just a few months before, were at the cellar of the NL. On the other side, the Chicago Cubs, the "lovable losers", who, for the first time in a long time, were so close to victory. The Cubs jumped to a quick 3 games to 1 lead including 2 out of the 3 games in Miami, and were the sure favorites to take the series when it shifted back to Chicago. In Game Five, an absolutely stellar performance by Josh Beckett brought the series back to Chicago, back to Wrigley Field, where the home team has always had the advantage. With the Cubs needing to win only one game, and having studs Mark Prior and Kerry Wood on the hill those two games, most people thought the Marlins hope was over. In Game Six, the Cubs enjoyed a comfortable 3-0 lead with one out in the 8th Inning, when it all fell apart, and the Marlins went on to win the game, tying the series. This was the game of the Steve Bartman incident. In Game Seven, Brad Penny drove it home for the Fish, clinching their second pennant in 6 years.

2003 World Series

In the World Series, the underdog Marlins prevailed over the Yankees, 4 games to 2. This World Series marked the 100th anniversary of the annual event, although because there had not been a World Series played in what would have been its second year (1904), and the cancellation of all post-season play as a result of the strike in 1994, it was only the 99th World Series played. Josh Beckett was named the World Series MVP.