Garrett was recalled from the alternate training site for Sunday's doubleheader against the Nationals.
The 23-year-old started during the doubleheader last weekend and will rejoin the Marlins a week later for another twin bill. Garrett earned the win and allowed one run on three hits with six strikeouts and two walks over five innings, so he could be tabbed to start Sunday's nightcap, though the Marlins have not given any official indication of who will take the mound.