Rosario went 1-for-4 with a solo home run in Friday's win over the Mariners.
The veteran outfielder took former Nats pitcher Austin Voth deep in the eighth inning to cap the scoring in a 6-1 victory, Six of Rosario's seven homers on the season have come in his last 16 games, a stretch in which he's slashing .302/.362/.698 with four steals, 13 runs and 15 RBI.