On July 16, 2017, Doolittle was traded to the Washington Nationals, along with Ryan Madson, for Blake Treinen, Sheldon Neuse, and Jesús Luzardo.
On July 16, 2017, Doolittle was exchanged to the Washington Nationals, along with Ryan Madson, for Blake Treinen, Sheldon Neuse, and Jesús Luzardo.