Hassell will start in center field and bat ninth in Sunday's game against the Phillies.
Hassell has now started four of the Nationals' last six games, with one of his absences during that stretch coming against a left-handed pitcher. With an .885 OPS since being called up from Triple-A Rochester on Aug. 1, Hassell has earned a regular spot in the rotation as Washington finds playing time for five young outfielders -- Hassell, James Wood, Dylan Crews, Daylen Lile and Jacob Young -- between the three defensive assignments and DH.