Three Royals Pitchers On the "Roster Bubble" to Watch in Spring Training

[Kevin O'Brien]

Image courtesy of Denny Medley-Imagn Images

Kansas City will begin its 2026 Spring Training campaign on Friday and Saturday against the Texas Rangers, who share the Surprise complex with the Royals. Safe to say, excitement and expectations are up in Arizona, especially with team workouts beginning this week.

The Royals have tried to answer some questions this offseason with a slew of acquisitions, both by trade and through free agency. That said, Kansas City didn't get that "big name" player that fans were hoping for this offseason. That probably puts the Royals slightly behind the Detroit Tigers in the AL Central preseason standings, especially after the Tigers acquired Framber Valdez and Justin Verlander to boost the rotation.

Speaking of starting pitchers, Kansas City has accumulated plenty of rotation depth since last year's Trade Deadline. In fact, two starters they acquired from San Diego at the Trade Deadline last season (Stephen Kolek and Ryan Bergert) are expected to start the Royals' first two Cactus League games this spring, according to MLB.com Royals beat writer Anne Rogers. 

The Royals' pitching depth is nice, especially after how hammered the rotation was in 2025 due to various player injuries. While Alec Marsh is expected to miss significant time again (he's already been placed on the 60-Day IL), there will be 3-4 starters on this Royals 40-man roster that will start the year in Omaha (barring injuries, of course) who could be in the Royals rotation most other years. 

There are three particular pitchers that Royals fans should pay attention to this spring, especially since the odds are against them when it comes to making the Opening Day starting rotation out of camp. Those pitchers are Bergert, Bailey Falter, and Mason Black, who have all been on the Royals roster for less than a calendar year.

However, while they are long shots to start the year in the rotation (or Major League roster in general), they are intriguing arms with some bounce-back upside, especially if they can make some tweaks to certain pitches. I will look at each pitcher's offerings and how they could affect their performance in Arizona this spring. 

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Ryan Bergert and the Breaking Ball

Bergert had a bit of an inconsistent rookie debut with both the Padres and Royals last season. In his first 11 appearances (seven starts) with the Padres, he posted a 2.78 ERA and 1.18 WHIP in 35.2 IP. However, his FIP was 4.28, his K/BB ratio was 1.89, and his fWAR was only 0.3. The right-hander primarily benefited from a .217 BABIP and 85.6% LOB% during his tenure with the Padres last year.

When he moved to Kansas City at the Trade Deadline, many of his underlying metrics improved. His FIP was 3.75, his K/BB ratio was 2.29, and his fWAR was 0.7. That said, the results weren't as impressive with the Royals. His ERA was 4.43, and his WHIP was 1.33. A big difference was that the BABIP rose (.289) and the LOB% dropped significantly (68.2%). 

The Royals, who shut Bergert down the stretch, are hoping that he can bounce back and iron things out with his command in 2026. While the pitch quality of his repertoire was solid last year, it didn't lead to many whiffs or encouraging xwOBACON numbers, as seen in his TJ Stats summary below. 

Bergert threw six pitches and produced an overall TJ Stuff+ of 105, which is impressive. He also sported five pitches with grades of 52 or higher and a 51.7% zone rate overall. Unfortunately, his chase rate was 25.1%, his whiff rate was 23.9%, and his xwOBACON was .373. Those are all mediocre marks, to put it nicely, and Bergert should produce better results with that kind of TJ Stuff+ profile. 

One thing Bergert seems to be working on this spring to help him overcome this issue is adding a new breaking ball. 

The former 6th-round pick in the 2021 MLB Draft primarily threw a slider (24.8%) and sweeper (18%) as his primary breaking offerings. However, both pitches sported chase rates under 30% and whiff rates under 34%. Those rated as subpar, especially compared to the league average in those categories, for those particular pitchers. 

The pitches are intriguing, especially when broken down individually. First, let's take a look at the heatmap and dataset for his slider, his most thrown breaking pitch last season. 

The slider seemed to produce the same kind of results against both lefties and righties. He did locate the pitch more in the middle against lefties and more glove-side against righties. That said, it had similar whiff rates (32.4% against LHP; 34.6% against righties), CSW (28.3% against lefties; 29.4% against righties), and xwOBACON marks (.378 against lefties; .364 against righties). 

Now, let's take a look at Bergert's sweeper, which he threw 6.8% less than the slider. 

The sweeper was a peculiar pitch, based on the heatmap and splits. Against lefties, he threw the ball more in the middle of the zone, and he didn't generate a lot of whiffs (20% whiff rate). That said, he had a solid xwOBACON (.257) and strong CSW (35.3%), showing that Bergert could throw strikes and minimize hard contact against the offering. Conversely, he generated a lot of whiffs with the sweeper against righties (40%), as well as O-Swing% (33.3%), with the CSW being okay (29.9%). However, his xwOBACON was much worse (.442). 

In the clip compilation of those two pitches, the slider was a harder, more vertical offering, while his sweeper was a loopier pitch. 

I'm wondering if there was too much of a pitch velocity difference between the sinker and the slider, and movement-wise, they profiled too similarly. That would have helped hitters tee off on both pitches, especially if they could pick up the movement early in the release. 

Bergert's pitch movement profile suggests that using his curveball more (he threw it only 8 times) could give him a breaking offering that keeps hitters from sitting on his sweeper and/or slider. 

The potential is there for Bergert to be an effective No. 3, 4, or 5 pitcher in the Royals' rotation in 2026 and beyond. However, using the curveball more and pitching it more effectively (though it had a 103 TJ Stuff+ in a limited sample) could help maximize his pitch mix and make his other breaking pitches more potent, especially in terms of whiff and chase rates. 

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Bailey Falter and the Sinker

Falter had a rough Royals debut after coming over from Pittsburgh at the Trade Deadline.

In four outings (two starts) and 12 IP with Kansas City, he posted an 11.25 ERA and 2.25 WHIP. Safe to say, he has entered Spring Training on shaky ground when it comes to a roster spot, especially with him not having a Minor League option. Then again, Royals GM JJ Picollo seems to have some confidence that Falter for 2026, as they tendered him a $3.6 million deal this offseason.

Even though the results weren't great, he does sport good extension on his pitches and some intriguing TJ Stuff+ metrics, as demonstrated below in his TJ Stats summary from last season.

The key for Falter is his four-seamer, which is rated as his best offering on a TJ Stuff+ end last season (101). He didn't generate a whole lot of whiff with the four-seamer (15.8%), but he did generate decent zone (55.5%), chase (24.7%), and xwOBACON (.356) on the pitch. It was also interesting to see how his four-seamer fared against lefties and righties last year, based on his TJ Stats heatmap data.

The four-seamer seemed to be more effective against lefties, though he threw it nearly 20% less than against righties. He threw it more in the middle of the plate against lefties based on his four-seamer heatmap, which doesn't seem ideal. And yet, against lefties, he had a better CSW (28%; 24.3% against righties), whiff rate (20%; 14.9% against righties), and xwOBACON (.306; .367 against righties). 

Falter mentioned in an interview on February 17th with Jack Johnson of 810 AM radio that improving his command and effectiveness of his four-seamer is a main focus for him this spring, especially in his work with new assistant pitching coach Mike McFerran. 

An interesting aspect of Falter's profile is that he also sports a sinker, which he threw only 9.8% of the time last year. And yet, despite its lower usage, he generated a better zone (64.8%) and chase (36.8%) rate with the sinker, as well as a more encouraging xwOBACON (.312). Here's what his heatmap looked like on the sinker last year.

Falter primarily threw the sinker against lefties (20.5% usage against LHB compared to 6.2% usage against RHB). However, the pitch produced a solid CSW (32%), whiff rate (15.1%), O-Swing% (48.6%), and xwOBACON (.298) against lefties. He also located it in a good area of the zone, based on his heatmap data: up and inside. 

Nick Pollack of Pitcher List recently made an intriguing point on Twitter about Cole Ragans, Noah Cameron, and Kris Bubic, and their lack of sinker usage, especially against left-handed pitchers. That got me thinking about Falter and his sinker usage.

Granted, Falter throws his sinker 20% of the time against lefties (which Nick advocates for with Ragans, Cameron, and Bubic). However, what if he threw it more against lefties AND righties? Maybe that percentage goes up to 15%, and he throws it 30% of the time against lefties and 10-12% against righties? Could Falter see an improvement in his results in 2026 with the Royals?

Honestly, the movement profile looks a lot better on his sinker than on his four-seamer, as shown in the clip compilation below.

Falter will need to have a strong Spring Training performance to keep his spot on the active roster (he will be DFA'd if he doesn't make it). Perhaps increasing the sinker usage (and lowering the four-seamer usage) could help strengthen his repertoire and make him more effective overall in 2026. 

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Mason Black and the Four-Seamer

The Royals traded for Black from San Francisco, and he may be one of the more intriguing projects this spring for McFerran and lead pitching coach Brian Sweeney. He was once a Top-10 prospect in the Giants' system, but he's posted a 6.47 ERA and 1.64 WHIP in 10 MLB outings totaling 40.1 IP over two seasons (2024 and 2025). 

Black only made one outing for the Giants last year, allowing three earned runs on five hits (including two home runs). However, he struck out five, allowed no walks, and sported some strong extension on his pitches as well as promising zone (55.4%) and chase (33.3%) rates. 

One pitch that could be key for Black this spring is his four-seamer, which he threw 43.2% of the time in his lone 2025 outing. Black flooded the zone with the pitch (59.4% zone rate), and the xwOBACON (.302) was the best mark of his five pitches. However, the TJ Stuff+ (95), chase (23.1%), and whiff (16.7%) rates were lackluster. 

Granted, that is only one outing. Thus, let's take a look at his TJ Stats summary from his stint in Triple-A Sacramento, where he primarily pitched in 2025. 

The four-seamer profiled similarly in terms of TJ Stuff+. Conversely, he actually produced better chase (25.4%) and whiff (30.2%) rates with the pitch against PCL batters last season. Thus, it's possible that Black could've produced more chase and whiffs with more innings pitched at the MLB level.

Let's take a look at the heatmap and splits data on Black's four-seamer from Triple-A and see if any trends emerge.

Against righties, Black was more effective at generating O-Swing% (23.6%), whiff (33%), and CSW (31.7%). However, his xwOBACON was super high at .449. He was better at generating a lower xwOBACON with his four-seamer against lefties, and the CSW (27.1%) and whiff rate (27.6%) were solid marks too. Thus, it would be interesting to see if he changes up the mix with his four-seamer in order to maximize the results in those categories in 2026, whether it's at Triple-A or the MLB level. 

The 26-year-old Lehigh product has an impressive-looking fastball movement-wise. When it's located effectively in the zone, it can be a go-to swing-and-miss pitch. That was the case last year when he struck out Lawrence Butler of the Athletics on an immaculately located four-seamer. 

On a positive note, it seems like the movement has been looking sharp this spring. Johnson reported that Black's run on his fastball looked impressive in a recent Tweet at Royals camp in Surprise. 

I am not sure if Black is "starter" material with the Royals. Honestly, he seems better suited for the bullpen, where his stuff and repertoire may play better in shorter outings. However, there is a need for starting depth in Omaha, so Black will likely fill in the Storm Chaser rotation at the start of the season, especially since he still carries a Minor League option.

That said, Royals fans shouldn't sleep on Black. If the four-seamer clicks, he could be an underrated contributor to this Kansas City pitching staff in 2026. 

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