Parker will serve as the opener for Game 1 of Tuesday's doubleheader against the Nationals, Mark Zuckerman of MASN Sports reports.

EDGE Analysis

Parker is expected to toss the first inning or two before handing the ball to the bulk reliever, though the Phillies have yet to reveal who will fill that role. The right-hander owns a 4.40 ERA and 1.24 WHIP with a 60:22 K:BB over 57.1 innings this season.