By rule, players with least six years of MLB service time who aren't under contract have 15 days after the World Series to declare for free agency.
What this means for the Marlins is that first baseman Nick Johnson and relievers Kiko Calero and Brendan Donnelly may file for free agency as early as today.
Another free agent possibility is first baseman Ross Gload, who has a $2.6 million club option for 2010. The Marlins aren't expected to pick that up. If they don't, Gload will join the free agent list.
As of Thursday, the Marlins hold exclusive negotiating rights with their eligible free agents for 15 days, or through Nov. 19. If the team and player don't reach agreement by then, the player is free to negotiate with all 30 big league clubs.
Johnson and Calero also are Type B free agents, meaning, if the Marlins offer them salary arbitration for the 2010 season, and they still sign elsewhere, Florida will receive a compensatory sandwich pick between the first and second rounds in next year's First-Year Player Draft.
Clubs only receive compensation if the player signs with another club before Dec. 1, or is offered arbitration and declines.
The Marlins could offer both Johnson and Calero arbitration, setting themselves up for supplemental draft picks in 2010 because it is unlikely either will return.
Should the club not pick up Gload's option, they can still sign the 34-year-old, who was a valuable pinch-hitter and bench player.
Johnson, 31, joined the Marlins at the July 31 non-waiver trade deadline for pitching prospect Aaron Thompson.
The left-handed-hitting Johnson, who had playoff experience while with the Yankees in 2003, provided plate discipline and gave the Marlins a lift in the second half after he was acquired at the Trade Deadline from the Nationals.
His salary was $5.5 million in 2009. On the open market, it is doubtful the Marlins would be able to afford Johnson, who appeared in 35 games with Florida and batted .279 with a .477 on-base percentage.
The Marlins have first base options in prospects Logan Morrison and Gaby Sanchez. The team also is in the process of deciding if it will bring back Jorge Cantu, who is arbitration eligible. Cantu made $3.5 million in 2009, and will make considerably more next year.
Cantu played first base before Johnson arrived, when he was switched to third base.
In the bullpen, Calero was a pleasant surprise who cost $500,000.
A non-roster invitee to Spring Training, Calero became one of the team's most reliable relievers. He appeared in 67 games, three shy of his career best while he was with the A's in 2006.
Calero's 60 innings pitched were a personal high, and he posted a 2-2 record with a 1.95 ERA, another career best.
Because he showed he was healthy, Calero likely pitched himself into a bigger payday elsewhere.
Donnelly, 38, was another impressive pickup. Signed in early July, the veteran right-hander appeared in 30 games, and he went 3-0 with a 1.78 ERA.
The Marlins have shown preliminary interest in bringing Donnelly back, but whether they get a deal done remains unclear.