Cash, who served as knuckleballer Tim Wakefield's personal catcher in 2008, is now a free agent.
Boston did tender 2009 contracts to the other 28 unsigned players on its Major League roster. First baseman Kevin Youkilis, closer Jonathan Papelbon and lefty specialist Javier Lopez are eligible for salary arbitration. The other 25 unsigned players on the roster can simply be renewed by the club.
As far as catching goes, the Red Sox have a lot of uncertainty at the position, which is partly to explain why they weren't comfortable extending a firm offer to Cash at this time.
Jason Varitek, Boston's starter behind the plate since 1999, is still a free agent. If Varitek returns, the Red Sox are hoping to find another catcher -- perhaps a prospect -- who can help take some of the load off of the 36-year-old captain.
Red Sox general manager Theo Epstein said at the Winter Meetings earlier this week that the club could go in basically any direction at catcher. There could be two veterans, two young players or a veteran and a young player.
Though the Red Sox were pleased with Cash's work on defense -- not just with Wakefield, but the rest of the staff -- he didn't pose much of a threat offensively.
In 61 games during the 2008 season, Cash hit .225 with three homers and 15 RBIs. Cash, 31, is a career .184 hitter in 187 games.
If Cash does not return, it will be interesting to see who catches Wakefield. Varitek caught the knuckleballer earlier in his career, but hasn't done so with any regularity since Terry Francona took over as manager in 2004.
Ian Browne is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.