Gomes, who has two homers and 10 RBIs this season, exited with a left forearm contusion. Gomes' left arm was hit by a pitch from Brewers' starter Jhoulys Chacin in the first inning.
Stevenson left the game with back spasms in the fourth inning.
Due to mechanical issues with the Nationals' charter plane in Philadelphia on Sunday, the team didn't arrive in Milwaukee until just after 12:30 p.m. ET on Monday, about seven hours before first pitch.