The Minnesota Twins front office has a checkered history of bringing in relief pitchers on low-cost, low-risk deals. Their success with identifying which can be high-quality options has been just as unstable.
For every Caleb Thielbar, there’s an Alex Colome.
For every Sergio Romo, a Joe Smith.
But they’ve seemed to have a knack for finding overlooked players by investing (used loosely) in free agents who only require a minor-league signing with an invite to spring training or claiming them off waivers from another club.
Brock Stewart is the most recent and most prominent example. In the offseason between 2021 and 2022, the former top prospect inked a “preferred” non-roster invitee contract. The Twins offered Stewart a two-year pact while he recovered from Tommy John surgery. Once he was healthy enough to take the mound for Triple-A St. Paul last year, it became clear that Minnesota had made a wise investment.
So, what separates Stewart from other low-cost additions the Twins have made to their relief corps recently?
Once healthy last season, Stewart threw noticeably harder than ever, even when he was a top prospect for the Los Angeles Dodgers. In those days, he was still developing to be a starting pitcher, and his fastball averaged a mediocre 91 to 93 mph. He carried a sterling 1.54 ERA with a whopping 47.8% strikeout rate in 10 appearances out of the Saints’ bullpen last spring, mainly due to his fastball approaching triple digits.
That was enough for the Twins to give him a shot at the big-league level, where he continued to impress.
Stewart shoved in 27 ⅔ innings pitched for the Twins, with an immaculate 0.56 ERA and a still-impressive 35.8% strikeout rate. Most importantly, he stranded base runners at a ludicrous 98% clip. That’s right, Stewart only gave up two runs in 28 MLB appearances.
Having that buzzsaw as a high-leverage option was excellent enough, but it also took some much-needed pressure off of closer Jhoan Duran and his primary set-up man, Griffin Jax. With the Twins mostly relegating Emilio Pagán to lower-leverage situations and Thielbar hitting the IL for almost the entire summer, Stewart stepped up and delivered when called upon.
Now, the club has Stewart penciled into high-leverage opportunities for 2024 and beyond.
Stewart isn’t the first low-risk reliever who has delivered for the Twins in recent years. Still, it feels like he’s locked into a spot on the depth chart while Minnesota moved on from other similarly successful relievers.
Take Matt Wisler, for example. The Twins picked him up off waivers from the Seattle Mariners in the fall of 2019. Wisler had a promising campaign with Minnesota in the pandemic-shortened 2020 season. He had a 1.07 ERA in 25.1 innings pitched that year and a similarly strong 12.4 K/9. His emergence propelled the team to a postseason berth, much like Stewart’s, all for the league minimum salary.
Tyler Clippard was another low-cost reliever who had a successful season for the Twins that year. They signed Clippard for a relative pittance before the COVID season, and he had a 2.77 ERA and 0.88 WHIP. However, Minnesota moved on from Wisler and Clippard at the end of the season. Clippard was a free agent, and the Twins lacked confidence in his stuff holding up at the ripe age of 36. But Wisler was only 27 and was due a modest $1.1 million salary in arbitration for the following year. But the Twins non-tendered him, and their bullpen in 2021 suffered greatly in his absence.
So why does the club have more confidence in a 32-year-old Stewart, who is both older and has a more recent and lengthy track record with injuries?
It could be a mix of a few factors. Stewart’s raw stuff was far more impressive in his Minnesota debut. He had a heater that averaged 97.2 mph. He also developed a sweeper and a cutter, rather than just a slider, which he used earlier in his career. Stewart also didn’t have nearly the same struggles with walks as Wisler (10.1% walk rate for Stewart, 13.1% for Wisler) while showing more swing-and-miss capability than Clippard (41.5% whiff rate for Stewart, 28.1% for Clippard).
The Twins think Stewart’s success is more sustainable. Maybe they’ve become less prone to leaning on their confidence in finding new scrap-heap relievers they can mold into bullpen weapons, even though that’s exactly what they did with their new set-up buzzsaw.
