The Marlins designated King for assignment Sunday.
The left-hander joined Miami on a one-year, $1.5 million contract in February and delivered a 1.95 ERA and 0.70 WHIP in his first 38 outings of the year, but he's surrendered 14 earned runs with a 4:9 K:BB in his past 12 appearances. Despite the recent struggles, King's early season performance could generate some interest on the waiver wire.