Grace was recalled from Triple-A Syracuse on Thursday, Jorge Castillo of The Washington Post reports.
Grace will offer a fresh arm out of the Nationals' bullpen after Trevor Gott logged 1.2 innings in Wednesday's 13-2 loss to the Braves. The 28-year-old owns a 4.05 ERA and 1:2 K:BB through 6.2 innings with the big club this season, so he likely won't see any high-leverage innings.