Grace (groin) tossed a bullpen session Sunday, Byron Kerr of MASN Sports reports.
The Nationals will likely check back in with Grace and see how feels a day after resuming mound work, but if he reports no issues with his left groin, he'll likely be cleared to begin a brief rehab assignment early this week. Grace could be activated from the 10-day disabled list at some point during the Nationals' upcoming road series in San Diego or Arizona.