DeJesus, 33, is batting .250/.330/.401 this season. For his career, he owns an OPS+ of 106 across parts of 11 major-league seasons. DeJesus is capable of playing all three outfield positions and this season has manned center on a regular basis.
He seems an odd fit for the Nats, who are set in the outfield with Bryce Harper, Denard Span and Jayson Werth . As well, DeJesus bats lefty, which means he's not a platoon match for Harper or Span. Handedness aside, though, he's certainly an upgrade over current fourth outfielder Roger Bernadina.
DeJesus' contract includes a very reasonable $6.5 million team option for 2014, which suggests that this move could be about more than the Nats' slim playoff hopes this season.