Joshua Palacios DFA'd by the Pirates after hitting .211/.286/.211 in 22 ST plate appearances.
This is what I have for current active former Nationals. There might be a few I've missed, especially if they're in the minors.
Position players:
Tres Barrera, TBR
Travis Blankenhorn, LAA (minors)
Jeimer Candelario, CIN
Michael Chavis, LAD (minors)
Bryce Harper, PHI
Derek Hill, MIA
Carter Kieboom, LAA
Joey Meneses, NYM (minors)
Joshua Palacios, PIT (DFA'd)
Anthony Rendon, LAA (IL)
Victor Robles, SEA
Eddie Rosario, LAD (minors)
Kyle Schwarber, PHI
Dominic Smith, NYY
Juan Soto, NYM
Michael A. Taylor, CWS
Lane Thomas, CLE
Trea Turner, PHI
Ildemaro Vargas, ARI
Jesse Winker, NYM
Pitchers:
Austin Adams, BOS
Jacob Barnes, TOR
Patrick Corbin, TEX
Erick Fedde, STL
Hunter Harvey, KCR
Joe La Sorsa, CIN
Patrick Murphy, TEX (minors)
Tanner Rainey, PIT
Erasmo Ramírez, MIN
Joe Ross, PHI
Max Scherzer, TOR
Hunter Strickland, TEX (minors)
Wander Suero, ATL (minors)
Jordan Weems, ATL
Also, as noted above, Nick Senzel, Harold Ramírez, Yadiel Hernández, Cory Abbott and Travis Blankenhorn are with the Tecolotes de los Dos Laredos of the Mexican League, and Joey Gallo, released by the CWS, is reportedly now trying to convert into a pitcher.