Marlins To Sign John King

The Marlins and left-handed reliever John King are in agreement on a one-year, $1.5MM contract for the 2026 season, reports ESPN’s Jeff Passan. He was non-tendered by the Cardinals back in November. Miami now needs to open two 40-man roster spots — one for King and another for righty Chris Paddack, who agreed to a one-year deal earlier in the week. Their 40-man roster is full, but one spot can be opened by transferring injured righty-hander Ronny Henriquez, who’ll miss the season following Tommy John surgery, to the 60-day injured list.

King, 31, spent three and a half seasons with the Rangers from 2020-23 before being traded to St. Louis at the ’23 deadline. He spent the next two and a half seasons in the Cardinals’ bullpen. The 6’2″ ground-ball specialist has a 3.70 ERA over his past 243 big league innings but is coming off a rough season in which he worked to a 4.66 earned run average with a career-low 12.6% strikeout rate in 48 1/3 innings.

While King has never been one to miss many bats, that 12.6% mark was still three percentage points south of his career mark entering the 2025 season. Last year’s 6.3% walk rate was a strong mark but still up from the prior season’s 5.6%. King’s 93 mph average sinker velocity was also its lowest since the 2022 season.

What King lacks in strikeouts, he at least partially makes up for in ground-balls. Opposing batters have an extremely difficult time elevating against the lefty’s arsenal. He sports a massive 61.5% ground-ball rate in his career and has run that number up as high as 66.9% (in 2023). As one might expect for an extreme ground-ball pitcher, King has done a nice job keeping the ball in the yard, with just 0.89 homers per nine frames in his major league career.

King has been more effective against fellow lefties than righties, holding same-handed opponents to a .251/.291/.337 slash in his career. Right-handers have hit him well, slashing .302/.353/.430 in 682 plate appearances.

The Marlins have been on the lookout for a lefty to join manager Clayton McCullough’s bullpen. Miami already had Andrew Nardi, Cade Gibson and Josh Simpson, but each comes with some degree of red flag. Nardi missed the 2025 season due to injury. Gibson logged a 2.63 ERA in 51 2/3 innings as a rookie last year but did so with sub-par strikeout and walk rates; metrics like SIERA (4.08) and FIP (3.76) weren’t nearly as bullish. Simpson posted decent minor league numbers but was rocked for a 7.34 ERA in 30 2/3 big league frames.

King, like each of the other three lefty relievers on Miami’s 40-man roster, has some question marks of his own. He has more of a big league track record than any of his new southpaw teammates, however — enough to give the Marlins some veteran experience but not so much that he’s a pure one-year rental. King enters the 2026 season with 4.148 years of major league service time, meaning he’s still controllable through the 2027 season via arbitration. He’ll need to pitch well enough this year that his team feels he’s worth giving a raise and keeping for an additional year, but if he can bounce back to 2021-24 form, he’ll likely do just that.