The infielder will report to minor league spring training.
The 31-year-old right-handed reliever is married to Desmond's sister Nikki.
The 36-year-old right-handed reliever is reunited with Ryan Zimmerman and Jamey Carroll.
The veteran catcher was with the Nationals in spring training last year.
The Nationals add two new managers to their minor league system and promote several coaches from within.
The Nationals will use Syracuse as their Class AAA affiliate for, at least, another five years.