3 sensible St. Louis Cardinals trade targets for KC Royals

LHP John King

The Cardinals' most appealing bullpen target is right-handed closer Ryan Helsley, one of the few success stories in their pitching pipeline. With 49 saves and a 2.04 ERA in 2024, Helsley is set to be one of the top prizes on the trade market. His price tag, though, would likely give most teams — including that Royals — serious pause. If Kansas City is looking for controllable, reliable relief without the sticker shock, lefty John King could be the smarter move.

King arrived in St. Louis via a 2023 trade with the Texas Rangers, included as part of the package for pitchers Chris Stratton and Jordan Montgomery — both key contributors to the Rangers’ World Series run that year. Initially seen as a trade sweetener, King has become a solid addition for the Cardinals, posting a 2.52 ERA and 1.23 WHIP since joining. While he won’t rack up strikeouts, averaging just 5.5 K/9 over 76 games, he keeps walks down, induces groundballs, and relies on strong infield defense to get outs.

King isn’t a reliever with much upside potential. He rarely induces swinging strikes, recording a career-low 7.9% whiff rate in 2024. However, he often gets ahead in the count and locates well against right-handed hitters. His sinker — thrown 58.8% of the time last season — was one of the most effective pitches on the Cardinals' staff. It’s his go-to, backed by a four-seam fastball and a changeup that help keep batters off balance.

The Royals bullpen could be lefty-heavy heading into 2025. Kris Bubic, Daniel Lynch IV, and Sam Long are a few of the notable southpaws Kansas City has at its disposal. However, with the team considering stretching Bubic and Lynch back out as starters, there’s a mild but present need for lefty relief. Long, Angel Zerpa, and newcomer Evan Sisk could be options, but they’re the only other lefty arms on the 40-man roster. King could bring some much-needed stability to that role in Kansas City.

King was the quintessential middle-leverage arm for the Cardinals last season. With 1.00 as an average leverage situation, King’s leverage when entering the game was exactly that — 1.00. He wasn’t reliable in high-leverage spots, but that’s never been his calling card at the MLB level. King is a dependable middle-innings guy against the bottom half of the order or when the matchup is favorable. Nothing more, nothing less.

King wouldn’t be a headline-grabbing acquisition, but he’d be a solid move to lift the floor of Kansas City’s bullpen while marginally raising its ceiling. Entering his first arbitration year, King has three years of team control remaining — likely covering his most effective seasons. With St. Louis potentially a couple of years away from contention, Kansas City could see value in maximizing King’s performance on a team-friendly contract. If they believe they can tap into his potential, this would be a smart, low-risk gamble.