The Marlins optioned Go to Triple-A Jacksonville on Saturday.
Go was part of the Padres' trade package to acquire Luis Arraez on Friday. Before the trade, Go was demoted to Double-A San Antonio, where he has posted a 4.38 ERA and 1.49 WHIP over 12.1 frames. He'll start his career in the Marlins' system with Triple-A Jacksonville and look to work his way to the big club.