The Marlins designated de Geus for assignment Sunday.
De Geus will cede his spot on the 40-man roster to right-hander Xzavion Curry, whose contract was selected from Triple-A Jacksonville in a corresponding move. The right-hander failed to win a spot in Miami's Opening Day bullpen during spring training and struggled in his first appearance of the season with Jacksonville on Friday, giving up four runs (one earned) on five hits over 1.1 innings.