A common refrain for the Nationals off-season so far has been that they have been smart to stay away from big free agents so as to not lock themselves into too many long term contracts and prevent their ability from re-signing their own players. The players most effected by this would be Desmond and Zimmermann as they are both free agents after the 2015 season, but let's look closer at the Nats 2016 payroll.
As it stands right now the Nationals have $47.67 mil committed to three players (Werth, Zimmerman, Gonzalez) for the 2016 season with several others arbitration eligible like Strasburg, Espinosa, and Harper. Their will be an increase from the arb players but as that depends on their performance and health it is way too early to even attempt to figure out what that money will look like. If Strasburg and Harper can stay healthy they will be two of the highest paid players in the game, but if we have learned anything from watching baseball it should be that the expected future is not always the most likely one.