It will be a big week not just for Kansas City Royals players, but pretty much every player in Major League Baseball in general.

Tuesday is the deadline for MLB teams to add Rule 5-eligible players to the 40-man roster to protect them from the December Rule 5 Draft (which typically takes place during the Winter meetings). Friday is also the deadline for teams to tender a contract to arbitration-eligible players (they do not necessarily have to come to an agreement, just need to be tendered an offer in order to stay on the roster).

The Royals have plenty of Rule 5-eligible players I have talked about on this blog, including pitchers Jonah Dipoto, Alec Marsh, and TJ Sikkema as well as catcher/infielder Logan Porter. They did already add utility player Samad Taylor to the 40-man roster to protect him from the December draft (Taylor was acquired from the Blue Jays in the Whit Merrifield deal), so it will be interesting if a couple of more names will be added by Tuesday’s deadline, even though it is highly likely that many more will go unprotected.

On the other hand, while Tuesday will be worth watching from a Royals fan’s perspective, Friday may be a more critical date for the Royals organization as a whole, especially since they have a plethora of difficult arbitration decisions to make.

Today, David Lesky of Inside the Crown discussed not only potential additions but also which Royals players on the current 40-man roster could be non-tendered on Friday.

And here it is. I wrote about the #Royals Rule 5 decisions, some 40-man spots that are likely in peril and even a few potential acquisitions from teams trying to purge their 40-man. https://t.co/bYKGYNyioX

— David Lesky (@DBLesky) November 14, 2022

And one of the biggest names that Lesky discussed as a potential non-tender candidate was Brad Keller, the Royals’ Opening Day starter in 2021.

A former Rule 5 pick, Keller has had quite the career in Kansas City since coming over in 2018. Keller has made 139 appearances (including 105 starts) and has pitched 633.2 IP over five seasons with the Royals. For his career, Keller has not just posted a 4.25 career ERA, but he has also accumulated 7.9 fWAR to boot.

For context, his fWAR total leads all Royals pitchers in that category since the 2018 season, according to Fangraphs.

Granted, a reason why Keller leads all Royals pitchers from 2018 to 2022 could be credited to him having accumulated the most innings over that timespan as well.

Only two Royals have thrown more than 400 innings over that five-year sample: Danny Duffy (403 IP; 4.8 fWAR) and Jakob Junis (417 IP; 3.4 fWAR). So, while Keller should be credited for eating innings for the Royals over the past five seasons, he hasn’t really had much competition from other Royals pitchers, especially in the rotation.

While Keller has been one of the Royals’ more familiar pitchers over the past half-decade, he has seen a tough stretch over the past couple of seasons.

After posting a 2.47 ERA in nine starts and 54.2 IP during the COVID-shortened campaign, Keller saw his ERA balloon to 5.39 in 2021 over 133.2 IP, and 5.09 in 2022 over 139.2 IP. Both ERA numbers were career-high marks, and his combined 1.8 fWAR in 2021 and 2022 is less than his fWAR in 2018 (2.6) and 2019 (2.2), his first two seasons in the Majors.

Unfortunately for Keller and the Royals, he has been trending in the wrong direction for the past two years.

And to make matters worse, he pretty much pitched himself out of the rotation in the second half of 2022 and was pretty much regulated to a bullpen role over the last two months of play.

After making 17 starts in the first half of 2022, he only made five after the All-Star break (he had 18 appearances overall). And it made sense why Mike Matheny and the Royals demoted him to the bullpen: Keller produced an ERA of 7.71 in 42 IP in the second half of play last year, according to his splits.

The Royals not only have a new manager and bench coach (they hired Paul Hoover from Tampa Bay for the role) but will have a new pitching coach in 2023. That could bode well for not just Keller, but the other starting pitchers on the Royals’ 40-man roster (and farm system overall). On the other hand, Keller will be entering his last year of arbitration and could be due for quite a pay increase, especially after making $4.825 million a season ago.

After struggling in the second half, not having a set spot in the rotation OR bullpen in 2023, and most likely carrying a high price tag in arbitration, is Keller worth keeping in Kansas City for one more season?

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Improved Four-Seam Fastball; Decline in Slider Effectiveness

When I talked about Keller being a bounce-back candidate going into 2022, my main focus was on his four-seam fastball, which was one of the worst pitches in baseball in 2021 on a run value-end, according to Savant.

The only pitch in 2021 that was worse than Keller’s four-seamer (+18 run value) was Jake Arrieta’s sinker (+21), which can be seen in the table below:

One would think that Keller would utilize his four-seamer less in 2022.

However, he increased its usage from 29.7 percent in 2021 to 35.3 percent in 2022. And as a result, the four-seamer actually improved not just in run value (+18 in 2021 to +5 in 2022), but in other categories as well, as one can see in the data set below:

While Keller generated fewer whiffs on the four-seamer in 2022, he was more effective with the pitch when it came to striking batters out as well generating less hard-hit contact.

Keller increased his K rate by 1.6 percent and put away rate by 0.9 percent with his four-seamer last season, which were both promising improvements. A big reason for Keller’s gains in putting batters away with the four-seamer could be credited to his improved command of the pitch from the 2021 season.

Royals fans can see below between the 2022 image (scroll to the right) and the 2021 image (scroll to the left) that Keller became more adept at hitting the edges of the strike zone with consistency. That in turn, led to more strikeouts last season in comparison to two years ago.

Here’s an example of Keller elevating his four-seamer effectively against left-handed hitter Austin Meadows of the Detroit Tigers at Kauffman Stadium back in early April.

So if Keller saw improvement in his four-seamer in 2022, what happened then? Why did he still produce an ERA over five?

His lack of effectiveness with the slider could be credited as the primary culprit.

Last season, Keller’s slider produced a run value of +7. That was not just his second-worst pitch on a run value-end, but also a dramatic change from his previous run values on the slider since 2019 when it became a primary pitch in his repertoire.

In 2019 and 2020, his slider was by far his best pitch by leaps and bounds (double-digit run values in the red, which is good). And even though he saw some regression on the pitch in 2021 in terms of run value, he did post-career-best whiff, K, and put away rates with the slider that year.

Last year though, not only did his K rate decline 10.3 percent with the slider, but his wOBA on the pitch increased by 36 points and his slugging increased by 81 points as well.

In fact, let’s look at his heatmaps from sliders that resulted in extra-base hits in both 2021 and 2022, and notice the difference in the location of those sliders last year.

At least in 2021, Keller’s slider mistakes were a little lower in the strike zone and closer to the edges.

Last season though, they were pretty much center cut, and it was common to see bombs like this one from the Dodgers’ Will Smith when Keller made those mistakes with his primary breaking pitch.

Should Keller come back to the Royals in 2022, it will be a priority for the new pitching coach to help Keller channel that slider command that he showcased from 2019 to 2021.

If he can see improvement with the slider again, and if it can be a primary positive pitch for him, it’s possible that Keller could produce an ERA line closer to his career average of 4.25 in 2023.

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Is Keller Just Too Expensive Now for the Royals?

When looking at his other metrics, Keller’s 2022 wasn’t nearly as bad as the 5.09 ERA indicated.

Keller’s xERA was 4.37, which was a career-best. His FIP was a 22-point improvement in that category from 2021, and his xFIP was 22 points better as well. He also improved his groundball rate to 52.4 percent (a 4.6 percent improvement), and he lowered his walk rate by 1.2 points as well (his 9.2 percent BB rate was the second-best rate of his career).

In the first half of the year, Keller was a much more palatable starting pitcher, and that can be seen in his monthly splits from a season ago.

Was he an ace?

Absolutely not. However, he was really good in April, pretty good in July, and not bad in relief in September. Take away a disastrous August (11.29 ERA), and his overall numbers probably would’ve been a lot easier for Royals fans to stomach (and he probably would’ve still been in the rotation as well).

It’s easy to focus on how bad that second half was for Keller and how deflating the end of the year was for him after showing so much promise back in April. That said, Keller certainly wasn’t much worse than Daniel Lynch or Kris Bubic, or Jon Heasley, and much like those three, Keller will probably benefit from a pitching coach not named Cal Eldred.

Unfortunately, the main issue with Keller is that he is projected to make anywhere between $7 and 8 million in arbitration.

Considering the Royals are a small market club that finished last year with a payroll of $88 million, and is projected to be around the $77 million mark for 2023 (according to Roster Resource), that AAV (average annual value) amount seems expensive for a swingman like Keller.

This, in turn, makes him a highly likely non-tender candidate for the Royals. This is especially true considering that he will be a free agent after 2023, and it’s unlikely that JJ Picollo will bring him back for 2024 and beyond unless something really miraculous happens.

The 11 eligible #Royals are projected to make $32.6 million. Add that to the three under contract for 2023 at $31.75 million and you've got $64.35 million.

Within the 11 is Brad Keller, who is a big-time non-tender candidate. Mondesi is at $3 million. Weaver is too.

— David Lesky (@DBLesky) October 10, 2022

Keller won’t be the lone difficult decision for Picollo in the coming days (Adalberto Mondesi will be another challenging one, even though his projected price tag is less than half of Keller’s). Furthermore, the Royals need pitching help badly, especially in the rotation. If the Royals can’t attract veteran free-agent talent or perhaps swing a trade (Lesky talked about some Rays targets like Ryan Yarborough and Jeffrey Springs for example), one could think that Keller could be of some value, especially if the Royals are able to find a pitching coach who can tap into his potential.

And yet, the Royals under Picollo seem poised to continue to push for change throughout the organization.

It started with hiring Matt Quatraro over the familiar Pedro Grifol. It has continued with the Royals hiring Hoover from the Rays for the bench coach instead of an internal guy like Vance Wilson or Scott Thorman.

It would make sense that the Royals would look elsewhere when it comes to filling in that “veteran” role in the Royals’ pitching rotation next season (and that is in addition to Zack Greinke)…

And save and apply Keller’s $7-8 million in another area of need for this Royals team this winter.

Photo Credit: Ron Schwane/Getty Images