Can Bubic and Hernandez help spark the Royals’ rotation (and other young starters too)?

Much to the surprise of Kansas City sports fans, the Royals have won three in a row, which included them taking the first of a three-game series at Kauffman Stadium against a really hot Detroit Tigers team who had previously swept the Royals the last time they visited Kansas City:

While the defense, and clutch hitting of Ryan O’Hearn and Carlos Santana certainly merited some fanfare, one of the more promising stories from Friday night was the stellar performance from Kris Bubic, who produced a quality start in his return to the Royals rotation:

With Danny Duffy and Brady Singer both on the 10-Day IL, the Royals will need Bubic and their other young starters to step up, especially if they want to build some good momentum into 2021. On Friday, manager Mike Matheny announced Daniel Lynch was going to be recalled from Omaha and make the start on Sunday, which was big news for the Royals top prospect who struggled initially in his first three starts at the Major League level (15.75 ERA in 8 IP).

However, while Lynch’s return will be important for the left-handed prospect, but also the Royals rotation as a whole, it is expected that Lynch’s return will be more focused on “development” rather than “results”. It is expected that Lynch will probably go through some growing pains in his second stint with the Royals. That being said, if he can show at least some incremental growth over the next two months, that will be an encouraging sign for 2022, even if the 2021 bottom line stats aren’t impressive by any measure.

On the other hand, the Royals will need pitchers to produce down the stretch, with their results just as important, if not slightly more, than just their development. Bubic, who has a 118.2 IP at the Major League league level, is one of those pitchers, as is Singer, when he returns off the IL. However, another pitcher who will be important down the stretch will be Carlos Hernandez, who will be making his second-straight start after a decent outing against the Orioles at Kauffman Stadium last Sunday.

If Bubic and Hernandez show progress over the next couple of months, Royals fans should feel good about the club’s outlook, especially from a pitching end, not just for 2022, but perhaps beyond as well.


Bubic and Hernandez are two pitchers on opposite end of the spectrum. Bubic is more of a finesse pitcher who lacks a plus fastball, but does possess a plus-plus changeup, and a curveball that is slowly getting better over the course of the season. As for Hernandez, it’s all about the heat, as he touches 100 MPH with regularity. That being said, Hernandez does offer a five-pitch mix, according to Baseball Savant, which shows that he is capable of being a more nuanced pitcher who is capable of starting, and not just being a bullpen asset.

When it comes to Bubic, his command will obviously be a key thing to pay attention to over the course of the next couple of months. The former Stanford product has seen a tick in walk rate this year, as it has increased from 9.9 percent last year to 11.7 percent this year. Furthermore, his strikeout rate has also decreased three percent from last year, another sign that his overall command is lacking. As a result, his overall percentiles, via Savant, do not look impressive, even after his solid last two outings:

However, the only percentile in the red, curve spin, could be a sign of what to pay attention to from Bubic this year. With a four-seamer that averages 90.4 MPH, it is not surprising that Bubic has seen a decrease in whiff rate on his fastball. He is only averaging a 19.4 whiff rate on the pitch, a four percent decrease from last year. However, his curve has been much more effective at getting swings and misses, as it is generating a whiff rate of 23.5 percent, an 11.9 percent increase from a year ago.

That being said, more whiffs don’t always equate to more effectiveness. The wOBA on his curve this year is .403, which is a huge increase from the .176 wOBA on his curve last year. The big issue with Bubic’s curve is that when he locates it down in the zone, especially in pitcher-friendly counts, he’s really effective with it. Unfortunately, he has hung it a bit too much this year, and hitters have made him pay, which explains why it’s been more inconsistent this season in terms of impact.

Here’s an example of Bubic’s curve being barreled when he hangs it up in the zone to an All-Star hitter like Shohei Ohtani of the Angels:

Now, here is a recent outing against the Reds right before the All-Star break, where he locates his curve properly against Reds slugger Aristides Aquino, which gets Bubic the strikeout:

In his last start, Bubic showed a lot more effectiveness with the curveball, which is a positive sign that he’s maybe got a better feel on it after the All-Star break. Let’s take a look at his player breakdown from Friday night’s start against the Tigers:

7-23 against Detroit at Kauffman Stadium

Notice how he posted a 36 percent CSW rate on the curve, which was fueled by seven called strikes. Thus, even if he’s not generating whiffs on it, he’s at least painting it on the edges to garner strikes, which is a sign of improved control and command on the pitch. Bubic’s best pitch will always be the changeup, and that was evident on Friday, as he generated a whiff rate of 42 percent on the pitch. But how his curve develops over the next couple of months could give Royals fans an idea of what he could provide the Royals rotation in 2022 and beyond.


Hernandez has been a much different pitcher from a year ago, as he has utilized a few pitches more than his small debut in 2020. According to Baseball Savant, he is throwing his four-seam fastball 18.7 percent of the time and his slider 15.7 percent of the time, which are 16.6 and 7.1 percent increases in usage on those pitches from a year ago. As a result, Hernandez has lessened the usage of his changeup (6.7 percent in comparison to 15.3 percent last year) as well as his sinker (36 percent to 49.4 percent a year ago).

But to Hernandez’s benefit, this change in repertoire has yielded positive results, as his whiff rates on nearly all of his pitches have increased from a year ago. This is a good sign that the young Hernandez, who only pitched in Low-A ball prior to 2020, is finally showing that he has what it takes to be an effective pitcher at the MLB level.

The four-seamer and slider though will be two interesting pitches to watch from Hernandez down the stretch, and especially tonight in game two of the weekend series against the Tigers.

The higher usage of a four-seamer is an interesting strategy by Hernandez, who primarily relied on his sinker in his first year at the MLB level. It makes sense for him to continue to make his sinker his primary pitch, as his sinker still generates a lot of velocity (98.2 MPH), and does have more natural movement than the four-seamer. However, his four-seamer has been a nice change of pace from the sinker, and it shows in the metrics. His four-seamer is slightly slower on average (97.4 MPH), but it generates a lower exit velocity on average on batted balls than the sinker (90.7 MPH to 96 MPH EV on the sinker), and the whiff rate on the fastball (28.6 percent) is only 0.4 percent lower than the sinker.

Here is an example of Hernandez pumping his four-seamer in the triple digits range for a strikeout against Home Run Derby runner-up Trey Mancini:

The four-seamer and Hernandez’s command on it over the next couple of months will be interesting to watch. Since he can throw that pitch and the sinker with such high velocity, it could be an effective combo, if pinpointed well. That being said, if he loses control of it, it could see some regression, and with the increase in usage from a year ago at the MLB level, one has to wonder if Hernandez will see that regression on the four-seamer anytime soon, especially as he returns to the rotation.

Other than the fastball, the slider has seen an effective increase in usage from a year ago, especially on a swing and miss basis. Let’s take a look at Hernandez swing and miss percentage chart from the past two years, according to Baseball Savant:

Notice how the slider went from a pretty mediocre pitch on a whiff basis to a pretty dependable one in just a year’s time. And he has done so by nearly doubling his usage of the pitch too, which is a sign that the pitch could be another effective breaking pitch to complement his curveball, which he throws 22.9 percent, and is the second-most effective pitch on a swing and miss end.

Here’s an example of Hernandez getting the Yankees’ Luke Voit to look silly on the slider at Yankee Stadium near the end of June:

Hernandez doesn’t always throw the slider consistently, which makes sense considering his curveball is more used and familiar to him. In his last start against Baltimore, he only throw the slider nine times, a 12 percent rate. And yet, he generated a 50 percent whiff rate on it, which was much better than the 17 percent whiff rate on the curve, which he threw 23 percent of the time, as evidenced in the table below:

7-18 start against Baltimore at Kauffman Stadium

I do not expect to see Hernandez jump his usage of the four-seamer and slider immediately. But it will be interesting to see if he slowly utilizes it more and more in a starting role, and what kind of effect it could have on his bottom line.

Because if it does help him be more effective on the mound over the next couple of months, he could make a case to be a regular part of the Royals rotation at the start of 2022.


Bubic and Hernandez are not the Royals’ two most important young pitchers. I would think most Royals fans would believe that to be Daniel Lynch and/or Brady Singer, Jackson Kowar, or even Asa Lacy, though Lacy’s most recent early exit and struggles in High-A Quad Cities have not been promising signs for the 2020 No. 4 overall pick:

That being said, Bubic and Hernandez may be two of the most important young pitchers to watch down the stretch in 2021, as they not only could have an effect on the Royals’ future plans, but they also could impact the Royals currently as well. It is tough to tell how long Singer will be out, though Singer, despite the frustrations with his lack of a third pitch, has been the most effective of the Royals’ young starters on a fWAR basis, as evidenced below:

Additionally, while Lynch and Kowar could bounce back in returns to Kansas City (I imagine it won’t be long until Kowar returns to the Royals pitching staff), I am not sure if Royals fans should be expecting all that much. Some progress from them would be nice, but that progress may not necessarily have a dramatic effect on the W-L record.

On the other hand, Bubic and Hernandez’s progress has and will have an effect on the Royals’ W-L record, especially if they continue to develop as expected. And if those two can finish the year strongly, perhaps that could have an impact on the other Royals young starters such as Lynch and Kowar…

And let them know that they need to meet that standard of success set by Bubic and Hernandez when they become regular parts of the Royals pitching rotation at the start of 2022.

Photo Credit: Ed Zurga/Getty Images

One thought on “Can Bubic and Hernandez help spark the Royals’ rotation (and other young starters too)?

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s