Grace was designated for assignment by the Nationals on Friday.
Grace has endured a rough second half with a 7.42 ERA and 1.72 WHIP in 14 outings, so he'll lose his spot on the 40-man roster with Roenis Elias (hamstring) and Hunter Strickland (paternity) rejoining the team. Grace could remain in the organization if he goes unclaimed on waivers.