Could A Move to Starting Help Turn Around Lucas Erceg's Career?

 One of the more disappointing players this year has been relief pitcher Lucas Erceg. When he was acquired at the Trade Deadline from the Athletics in 2024, Erceg looked to be exactly what the Royals needed in the bullpen. 

In 23 IP and 25 appearances with the Royals in 2024, the former Cal product posted a 2.88 ERA, 0.84 WHIP, 1.88 FIP, and an insane 28.9% K-BB%. From August 1st until the end of the year, Erceg was arguably one of the most dominant relievers in the American League, and his Statcast percentiles that season proved it.

Unfortunately, the last two years haven't been as rosy for the right-handed reliever. 

Erceg seemed to be bothered by a lingering minor back injury. Despite this, he still pitched 61.1 IP and posted a 2.64 ERA and 1.17 WHIP. While those numbers were impressive on the surface, the more advanced metrics weren't as kind.

Erceg's FIP was 3.46, and his K-BB% was 12%, down from his overall 22.1% K-BB% with the Athletics and Royals in 2024. The biggest red flag was his decline in K% from 2024 to 2025. After producing a 28.5% K% in 2024 with the A's and Royals, he saw his K% regress to 19.4% in 2025. Furthermore, his whiff rate went from 31% in 2024 to 24.7% in 2025, and his CSW% went from 32.2% in 2024 to 27% in 2025. 

He also saw lackluster percentile rankings across many categories in 2025, per TJ Stats. 

It wasn't as if Erceg was bad in 2025. He was still one of the Royals' best relievers, even though he wasn't the primary closer (that role belonged to All-Star Carlos Estevez). That said, he wasn't as elite in 2025 as he was in that brief tenure in Kansas City in 2024, especially in their push to the postseason (and in the playoffs against Baltimore and New York as well). 

This year has been even worse for Erceg, as he looks like a shell of his 2024 Royals or former Athletics self.

In 38 games and 37 IP, he has a 5.11 ERA, 1.62 WHIP, 4.99 FIP, and 3.6% K-BB%. His K% is 16.4%, down 2.9% from a year ago, and his 24.2% CSW is 2.8% down as well. To make matters worse, Erceg has seen a spike in home runs allowed this year. His 13.8% HR/FB% is 5.3% higher than a year ago. 

One would think that Erceg may be seeing a decline in his velocity or stuff. And while the TJ Stuff+ numbers have seen a regression, his fastball velocity still ranks in the upper percentiles of the league. Unfortunately, most of his other percentile ranks are near the bottom, as illustrated below.

Erceg is not a lost cause based on this Statcast profile. He's still limiting barrels and exit velocity on batted balls at a decent clip, and his extension is encouraging as well. Unfortunately, when it comes to generating whiffs (26th percentile) and strikes in general (24th percentile zone rate), he's seen a massive regression, and he's been hard to utilize in high-leverage spots for the Royals, which was far from the case in 2025 and 2024.

So what do the Royals do with Erceg, especially at 31 and with his first year of arbitration eligibility this offseason?

Instead of just trotting him out in relief and "hoping" he figures it out, the Royals should take a risk and do something bold with  Erceg's development: 

They should transition him to a starting role.  

Why This Makes Sense for Erceg

Now, at 31 years of age, some Royals fans may be asking this: Isn't Erceg too old for this? Well, not really, especially when one looks at his current roster status.

Erceg has 2.136 years of service time, according to Fangraphs. That allows him to be still optioned to Triple-A Omaha. Erceg has all three Minor League options remaining, so he can move down to the Minor Leagues to work on this transition, if necessary.

Considering the Royals are 21 games under .500, this may be the best opportunity for Erceg to make this move. He's not really helping the bullpen right now anyway. By going down to Omaha (or the Complex League or Double-A Northwest Arkansas, if necessary), he gets to work on stretching out as a starter. In contrast, a reliever or another pitcher in the Minor Leagues (Steven Zobac, perhaps) gets a shot to prove if he can be a part of this Royals pitching staff in 2027 and beyond.

Now, Erceg also could make the transition to the rotation more easily than some relievers. Unlike some pitchers, he is not a 2-pitch pitcher like some typical relievers. Erceg sports four pitches in his repertoire, with three of those four posting TJ Stuff+ marks at or above average this season, according to his TJ Stuff+ summary below.

His slider (102) and changeup (107) are his best offerings, with his slider (102) being his third-best on a TJ Stuff+ end. His four-seamer doesn't rate well on a TJ Stuff+ end (96), but it has above-average velocity at 97.2 MPH. Furthermore, not only does he have above-average velocity on three of his four offerings, but he also varies his pitches, with three of his offerings (four-seamer, slider, and sinker) being thrown 25% or more (his changeup, while utilized the least, still is thrown 13.9% of the time). 

That's a strong base for the Royals Pitching Development team to work with. With a four-pitch mix, three decent pitches, he could transition to the rotation and focus more on sharpening the quality and usage over more innings of work. Furthermore, he could add a pitch or two, which would not only diversify his repertoire but also perhaps enhance his other offerings, especially his whiff rate, which is below average at 21.5%. 

What's interesting about Erceg's history is that he once had five pitches while with the Athletics. He threw a cutter in 2023, and the pitch performed decently, according to TJ Stuff+ summary data.

He threw the cutter only 4.5% of the time in 2023, which is minuscule. He also struggled to throw it for strikes, as evidenced by his 21.3% zone rate. Because of those factors, hitters tended to lay off it, only chasing 13.5% of the time. And yet, when they did swing, they were often unsuccessful. His cutter had a 40% whiff rate and a .354 xwOBACON, both above-average marks. 

As a reliever, it makes sense that he eliminated the pitch in 2024. Relievers should have quality pitches, even if it's fewer. As a starter, however, a more diverse pitch mix is necessary. Erceg bringing back the cutter, and perhaps adding another breaking ball (a sweeper or curve), could help give him the arsenal he needs to succeed in the transition to starting.

Furthermore, moving to the rotation could help him find a more even keel on the mound. Erceg is known for his intensity, and he demonstrated that on May 2nd when he accidentally cussed during a postgame interview with Joel Goldberg due to the adrenaline of closing out the game.

I wonder if that high adrenaline is having a counterproductive effect on Erceg now, especially as he is struggling this year. Thus, moving to the rotation could perhaps get his composure back and help him focus more on his pitches and mix rather than those highly stressful spots later in games where everything is riding on him for an inning.

Being a starter again could not just help him get his career back on track. It could also help him become a better pitcher, especially since he'll be able to work intentionally more on his mix and pitch quality. Those skills would be transferable, even if he moves back to the bullpen if the starting experiment doesn't go right. 

There Are Success Stories For Erceg to Follow

We typically hear success stories of pitchers moving from the rotation to the bullpen to revitalize their careers. Wade Davis is the most well-known one, as he went from a mediocre starter with Tampa Bay and Kansas City to being one of the best closers in the game from 2014 to 2017. 

However, there have been success stories. The Rays' Griffin Jax, the Mets' Clay Holmes, and even the Royals' own Seth Lugo are examples that Erceg could emulate.

Jax was moved to the rotation during the season after a brutal start as the Rays' initial closer. After posting an 8.00 ERA in 9.0 IP as a reliever, he transitioned to the rotation and posted a 2.80 ERA in 61 IP. When looking at his splits from last year and this year, not much has changed in his percentiles, though he has thrived as a starter despite a lackluster zone rate.

Despite the inconsistent control, he still generates whiffs, CSW, and GB%. Those are all traits that Erceg has demonstrated in the past (including the lackluster zone rate this year). 

Holmes is another arm that made the transition from a beleaguered reliever with the Yankees to a dependable starting pitcher with the Mets. As a starter in 2025, he posted a 3.53 ERA and 1.9 fWAR in 165.2 IP. He was actually having a better year this year with a 2.39 ERA in 52.2 IP before going down due to a fibula injury that put him on the 60-Day IL. 

When looking at his Statcast comparison from 2024, his last season as a reliever, to 2025, his first season as a starter, Holmes actually saw a lot of his percentiles decline. And yet, despite regression in many categories as the load increased, Holmes still managed to be a valuable and dependable starter for the Mets a season ago.

Holmes regressed heavily in generating whiffs, CSW, and strikeouts. That said, his ability to generate groundballs and limit barrels continued in Queens. As a result, he had a successful year as a middle-of-the-rotation starter. Erceg has demonstrated the same ability as Holmes to limit barrels and induce a lot of groundballs. Thus, it's feasible to see Erceg develop into a Holmes 2.0 if given the opportunity.

Lastly, let's take a look at Lugo, who went from a quality reliever with the Mets in 2022 to a starter with the Padres in 2023. The former AL Cy Young finalist saw a decrease in whiffs and CSW, but an increase in zone rate, strike rate, and groundball rate in the transition. 

The results for Lugo in 2023? A 3.57 ERA and 2.9 fWAR with the Padres in 26 starts and 146.1 IP. That performance earned him two big paydays from the Royals. 

Thus, it's not out of the realm of possibility that Erceg could find success as a starter like Jax, Holmes, or Lugo. Erceg shares many of the same profile traits as those three pitchers. Furthermore, like all three of those pitchers, Erceg has nothing to lose with a move from the bullpen to the rotation.

It will require some time in the farm system, perhaps for the remainder of the year, depending on how quickly he adapts. 

That said, there is a path for Erceg to find success in this move. Jax, Holmes, and Lugo did it. 

Hopefully, the Royals will help Erceg be the next reliever-to-starter success story.