2025 rebound, coaching link could make former Twins reliever a Royals target

Predicting what a team will do in their bullpen can sometimes be the most volatile exercise in baseball. No one saw the Kansas City Royals adding John Schreiber ahead of 2024's spring training, or Kansas City trading for Lucas Erceg or Hunter Harvey at the 2024 trade deadline.

Relievers are a very fluid commodity in baseball, with many playing for multiple teams in one season or hopping from team to team after their team control expires.

But it is easy to say the area needs to be addressed and that applies in Kansas City to the left-handed relief options for manager Matt Quatraro. No matter how it looks, new blood needs to be brought in to address that soft spot.

How that looks is up to debate. While options on the trade market exists, there are too many left-handed free agents available to ignore. One such free agent, reliever Caleb Thielbar, has a few traits that will make him a sensible addition for the Royals.

A former foe in Caleb Thielbar could be a Royals relief solution in 2026.

Thielbar is fresh off one of the bigger relievers rebounds we saw, after departing the Minnesota Twins for the Chicago Cubs.

After an uncharacteristic 2024 season where Thielbar had a 5.32 ERA and was worth 0.2 fWAR across 59 games, the southpaw was worth 1.1 fWAR in 67 games for the Cubbies with a 2.64 ERA and 3.00 FIP. In his age-38 season, the veteran was incredibly consistent for his new club and only allowed two hits in 3.2 postseason innings for Chicago.

Thielbar has had an unorthodox MLB career, including no big-league action from 2016-2019 and even becoming a collegiate pitching coach for a time. Since he will be 39 on Opening Day, it is unclear if Thielbar will look for another professional opportunity this offseason. Why should he come to Kansas City?

A few reasons come to mind, but a familiarity between Royals assistant pitching coach Zach Bove from his time in Minnesota comes to mind.

Bove was the Twins' assistant pitching coordinator from 2021-2022, two seasons where Thielbar tallied 123.1 innings across 126 games. Prior to Thielbar's 2025, those aforementioned seasons were Thielbar's best by fWAR and he struck out 30.7% of the opposition. Correlation doesn't always equal causation, but the timing is interesting.

Also, Thielbar's stuff hasn't waned as his arm stacks up innings and he gets older. His velocity hasn't dipped from year to year, while his slider and curveball earn 119 and 124 Stuff+ grades, respectively.

There is still life in the South Dakota State's arm if he chooses to continue playing. Considering his age as well, he may not garner a multi-year contract, and after signing with the Cubs for one-year, $2.75 million last offseason, even a moderate raise wouldn't break the Royals' bank.

This isn't even considering the veteran presence, the AL Central tie, or his success in Kauffman Stadium in recent years.

Overall, if Kansas City rightfully chooses to add a lefty reliever this offseason, they need to do so prudently. Fans may see "veteran southpaw" and think of Will Smith in 2024, but Kansas City has learned from their mistakes and Thielbar is a different pitcher now than Smith was then.

Here's hoping for a pairing benefitting both parties in 2026.