The Terps combined for 36 hits between both games.
The Terps fell behind in the first inning for the fourth straight game.
Right-hander Sean Heine was tagged for five runs in the first inning.
It's the third time Costes has earned the award this season.
The Terps racked up a season-high 18 hits.
Maxwell Costes and Randy Bednar belted 3-run shots to win Saturday's nightcap.