Machado was recalled from Triple-A Rochester to serve as the 27th man in Saturday's doubleheader against the Rockies, Mark Zuckerman of MASNSports.com reports.
Machado earned a spot on Washington's Opening Day roster this year and posted a 2.45 ERA and 1.18 WHIP in 11 innings over 10 relief appearances in April. The right-hander will provide additional bullpen depth during Saturday's twin bill.