Five of the Yankees' potential free agents formally filed for free agency on Monday, beginning what surely will be a busy winter for Brian Cashman. Alex Rodriguez, Jorge Posada, Mariano Rivera, Doug Mientkiewicz and Luis Vizcaino all filed and can begin open negotiations on Nov. 12. The Yankees retain exclusive negotiating rights until then. They are expected to go all out to re-sign Posada and Rivera, each in line for an estimated three years and $40 million.