ST. LOUIS -- Jason Isringhausen formally filed for free agency on Saturday, bringing the number of free agents from the 2008 Cardinals back up to six.

Isringhausen is the second-longest-tenured member of the club, having signed before the 2002 season. However, he lost his closing duties during the '08 season, and was placed on the disabled list for the final six weeks of the season due to an elbow injury.

The Cardinals have publicly expressed some interest in bringing Isringhausen back, though it's unclear how much room St. Louis has in its 2009 bullpen. Isringhausen is the franchise's all-time saves leader and a two-time All-Star.

The previous filers from the '08 Cardinals were Braden Looper, Russ Springer, Ron Villone, Felipe Lopez, Cesar Izturis and Jason LaRue. LaRue agreed to a new one-year deal on Friday.

Other potential candidates to file are Mark Mulder and Juan Encarnacion. The club holds a 2009 option on Mulder but has said that it will decline the option. Encarnacion is also eligible for free agency, but it is unlikely that Encarnacion will be able to resume his career as he attempts to recover from an eye injury he suffered in 2007.

Teams hold exclusive negotiating rights with their own free agents for 15 days after the World Series ends. That means that the six players can only negotiate with St. Louis until Friday, Nov. 14. They may speak with other teams, but not about contract specifics.