The Nationals selected Baker's contract from Triple-A Rochester on Sunday.
The son of longtime manager and former MLB outfielder Dusty Baker, Darren will get his first taste of the big leagues at age 25. The left-handed Baker lacks power (no home runs in 483 plate appearances at Triple-A), but he makes good contact (18.8 percent strikeout rate, .285 average) and brings speed to the table (38 steals in 43 attempts). He'll serve in a utility role for the Nationals in September and saw action at second base, left field and center field for the Triple-A club this season.