Ashby will serve as the opener ahead of Chad Patrick on Friday against the Nationals, Jack Stern of BrewerFanatic.com reports.
The Nationals typically have four lefties in the top five of their lineup against right-handed pitching, so opening with a lefty before turning the ball over to Patrick makes sense. Ashby already leads the majors with seven appearances this season and has a 3-0 record, 2.79 ERA, 1.23 WHIP and 14:5 K:BB across 9.2 innings.