The Nationals requested unconditional release waivers on Robles on Saturday.
Robles was designated for assignment Monday, and the Nationals will now opt to let him go rather than sending him outright to one of their minor-league affiliates. The 27-year-old has slashed .120/.281/.120 across 33 plate appearances in the majors this season, but he should be able to contribute for another outfield-needy organization -- even if only in the minors.