The Nationals' high Single-A affiliate faces an elimination game on Tuesday night.
The Potomac Nationals are down in their best-of-five 2013 Mills Cup championship series after dropping the first two games of the series at home against Salem.
The Salem Red Sox shut out the P-Nats 4-0 Sunday thanks to right-hander Mike Aguilera's 6 2/3 scoreless innings.
It was only the sixth game all season the P-Nats had been shut out. They managed six hits. Cutter Dykstra and Randolph Oduber each had two hits.
P-Nats left-hander Brett Mooneyham (0-1) allowed only two earned runs over four innings, walking four in the hard-luck loss. Paul Demny went 2 1/3 innings and also allowed two earned runs.
P-Nats relievers Travis Henke and Rob Wort combined for 2 2/3 scoreless innings to finish the game.
Game 3 of the Mills Cup championship series will be played at LewisGale Field in Salem, Va., on Tuesday with the first pitch set for 7:05 p.m.
Potomac has not announced its starting pitcher while the Salem Red Sox will send right-hander William Cuevas (0-0, 0.00) to the mound.