Mbaamin is exactly right that two players from the 2003 draft have been added to the 40-man roster to protect them from the Rule 5 draft.
I meant to mention yesterday that transactions were very likely since it was the final day to set the 40-man roster before the Rule 5 draft, but I forgot.
Since the Marlins only have 37 players on the 40-man roster they can enter into the Rule 5 draft, if they so choose. If a team has a full 40-man roster, they are prohibited from participating. Once a player is chosen in the draft they are immediately added to the 40-man roster and if a team doesn't have an available slot they can't pick a player. All roster moves have to be made ahead of time.
Of course, that doesn't mean the Marlins are going to select anyone at the Winter Meetings, but if they want to, they can.