After the World Series ends, players that are eligible become free agents. There are six Red Sox players from the 2012 roster that are now free agents. They are: David Ortiz, Cody Ross, Daisuke Matsuzaka, James Loney, Aaron Cook, Vicente Padilla, and Scott Podsednik.
The Red Sox will likely keep David Ortiz and sign him to a two year deal. They have also said they would like to bring Ross back but that is not a given. As for the other six free agents, Padilla is the only one that the Red Sox would like to retain.