Bill Ladson of MLB.com reports that the Nationals are interested in adding free agent catcher John Buck to serve as a backup to Wilson Ramos. Ladson reports that the team is looking for an established backup who would be able to play full-time should Ramos suffer a significant injury. The 33-year-old backstop came out of the gate strong in 2013, but limped home with a .222/.288/.278 slash with one homer and 14 RBI in the second half of the season.