Marlins DFA LHP John King, Recall RHP Jack Ralston for MLB Debut

The Miami Marlins designated left-hander John King for assignment and recalled right-hander Jack Ralston from the minors, per Christina De Nicola of MLB.com. Ralston, a reliever, is set to make his MLB debut in the move.

King's designation opens a spot on the active roster that Ralston steps directly into. What remains unconfirmed is any timetable or destination for King under the DFA process, as well as the specific circumstances that prompted the timing of the swap.

Per beat reporter Craig Mish, Ralston was being called up from the minors. The club's official account also announced the move, making this one of those roster transactions that arrived from multiple directions at once.

What to watch

Ralston's debut is the thread worth following here. How the Marlins deploy him out of the bullpen — and how quickly — will be the first real data point on what the organization expects from him at the big-league level.