The Marlins released King on Wednesday.
King had been removed from the Marlins' 40-man roster and is now officially a free agent after passing through waivers. The sinkerballing lefty had a 1.95 ERA in his first 38 outings of the season, but he lost his job after being rocked for 14 earned runs with a 4:9 K:BB in his past 12 appearances. King could have to accept a minor-league contract if he wants to sign somewhere for the rest of the season.