How Are the Relievers-Turned-Starters Performing So Far?

A handful of established relief pitchers have taken on starting roles in 2024. How are they looking one week in?

Reynaldo López of the Atlanta Braves poses for a photo during the Atlanta Braves Photo Day at CoolToday Park.
NORTH PORT, FL - FEBRUARY 23: Reynaldo López #40 of the Atlanta Braves poses for a photo during the Atlanta Braves Photo Day at CoolToday Park on Friday, February 23, 2024 in North Port, Florida. (Photo by Kelly Gavin/MLB Photos via Getty Images)

Plenty of relievers begin their careers as starting pitchers, but it’s far less common to see the opposite transition; it’s not so often a bullpen arm successfully makes the jump back to the rotation. After all, most relievers move to the ‘pen because they struggled as a starter. If they find success in their new role, why mess with a good thing?

Yet, the call of the rotation is strong. For players, it often means higher salaries. Even mid-rotation starters get paid more than all but the very best relievers. For teams, it means more innings out of the same roster spot.

Consider Zack Littell, who made headlines last year when he moved into the Rays rotation partway through the season. He saved a Rays team that lost several key starters to the injured list, and he earned himself a nice pay raise this winter in return.

Seth Lugo is another recent example. A free agent for the first time last winter, he bet on himself, deciding he would only sign with a team that would give him another chance to start. The Padres were that team, and their agreement worked out swimmingly for both sides.

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Lugo was the second-most productive pitcher for San Diego last season. He turned that success into a three-year, $45 million contract with the Royals this winter.

In one last notable example, Ronel Blanco moved back to the rotation in the minors last year. He was nearly 30 years old and had not been a starter since his age-23 season in 2017. His 2023 numbers weren’t particularly notable, but he did enough to secure a temporary role in Houston’s starting rotation this year. Surely, you know what happened.

In his first start of the 2024 season, Blanco threw a no-hitter.

This season, it seems like more relievers than usual are attempting to become starters. More still will inevitably make the transition throughout the year as injuries pop up.

For now, let’s take a closer look at the four established relievers taking on starting roles in 2024.

Jordan Hicks, San Francisco Giants

2024 Stats1 GS, 5.0 IP, 0 ER, 3 H, 1 BB, 6 K
Pitch MixSI (44.4%), SW (25.9%), SF (17.3%), 4S (12.3%)
Average Fastball VelocitySI (97.1 mph), 4S (98.1 mph)
Pitch metrics via Baseball Savant

Jordan Hicks, then a member of the St. Louis Cardinals, threw the fastest pitch in the National League last season. It was a sinker, clocking in at 104.3 mph. Jhoan Duran of the Twins was the only other pitcher in baseball to top 104 on the radar gun.

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Hicks was one of only six arms to average triple-digits on any pitch (min. 100 pitches). He was the only pitcher to average triple-digits on two distinct offerings. The man throws serious heat.

Hicks was never going to maintain that velocity as a starter, but he came pretty darn close in his first start of the season. His four-seam fastball topped out at 99.5 mph, while his sinker reached 99.1 mph. Even more impressive, his velocity didn’t drop throughout the game. That 99-mph sinker? It was the final pitch of his day.

Aside from maintaining velocity, one of the most important things a reliever can do when he moves to the rotation is add an extra pitch. Hicks didn’t exactly add to his arsenal, but he significantly increased his splitter usage in his debut start. Never before has he thrown more than two pitches at least 12% of the time; last Saturday, he threw four pitches at least that often.

Hicks needs to work on his splitter command, but when he throws it where he wants to, it looks like a nasty pitch. Only three of his 14 splits wound up in the strike zone, but the pitch still accounted for four of the eight whiffs he induced.

Hicks did all the right things in his first start of the season. He maintained his velocity. He mixed in four different pitches. Best of all, he limited walks.

Since his debut in 2016, Hicks has thrown 248.1 big league innings. More than 400 pitches have thrown at least that many innings in that time. Only eight have issued walks at a higher rate than Hicks.

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Yet in his debut start, Hicks walked just one of the 20 batters he faced. He didn’t sacrifice strikeouts, either. His 30% strikeout rate would be the best of his career.

Now, Hicks has to prove he can keep doing all the right things over a full season. Piece of cake, right?

Garrett Crochet, Chicago White Sox

2024 Stats2 GS, 13.0 IP, 2 ER, 8 H, 1 BB, 16 K
Pitch Mix4S (51.1%), SL (31.1%), CT (14.4%), CH (3.3%)
Average Fastball Velocity4S (97.0 mph)
Pitch metrics via Baseball Savant

Garrett Crochet is brand new to the rotation – and not just the White Sox rotation. Before this year, Crochet had never started a game in his professional career. He made a handful of starts during his time at the University of Tennessee, but even then he often pitched in relief.

It’s rare to see a reliever drafted with such a high pick (Crochet was taken 11th overall in 2020), but clearly, the White Sox saw something they couldn’t pass up in the young hurler. He made his MLB debut three months after he was drafted, becoming the first player in a decade to go straight from the draft to the show without playing in the minor leagues.

After a strong cup of coffee in 2020, Crochet was electric in his first full season. Over 59 total appearances from 2020-21, he twirled 60.1 innings with a 2.54 ERA and 2.63 FIP. His fastball got the job done in the mid-to-high-90s, while his sweeping slider was a nasty weapon. His changeup, considered by many to be the weak point of his arsenal, turned out to be an effective out pitch against opposite-handed hitters, helping the southpaw succeed against lefties and righties alike.

Crochet showed so much promise in his rookie season that some thought he could move to the rotation in 2022. Unfortunately, a UCL injury crushed those rumors, and it would take another two years before Crochet started his professional game.

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On February 27, he started his first spring training game, going 1.2 scoreless innings against the Dodgers. His next spring start was nearly a month later; he went 3.2 innings against the Royals, giving up three runs on five hits.

A week later, Crochet was starting for the White Sox on Opening Day.

Perhaps that said more about the depleted White Sox rotation than Crochet himself, but if the early returns are any indication, Crochet might be an ace after all.

His fastball velocity is slightly higher than when he pitched out of the bullpen. He has added a fourth a pitch, a cutter, and it looks good. He has gone deep in both of his first two starts while striking out eight batters each game. The pitch modeling system PitchingBot is utterly enamored with Crochet, while Stuff+ likes what he’s got as well.

The biggest question facing Crochet is how long he can keep this up. At this pace, he’ll surpass his career innings total in no time, and it’s hard to imagine he’s ready to pitch a full season. Still, as long as he stays healthy, I hope the White Sox let him try.

Reynaldo López, Atlanta Braves

2024 Stats1 GS, 6.0 IP, 1 ER, 4 H, 2 BB, 5 K
Pitch Mix4S (65.9%), SL (24.4%), CB (8.5%), CH (1.2%)
Average Fastball Velocity4S (94.9 mph)
Pitch metrics via Baseball Savant

Reynaldo López has the most experience starting out of the four pitchers in this post. He was serviceable as a back-end starter for the White Sox in 2018 and ’19 (4.64 ERA, 4.7 fWAR in 65 starts) before a couple of rough and injury-plagued seasons in 2020 and ’21 pushed him into a full-time bullpen role for 2022.

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After a couple of strong years as a reliever, López is giving it another go in the rotation. As to be expected, his fastball velocity was down a few miles per hour in his debut start. Still, it sat in the mid-90s, right around where it was during his two productive seasons as a starter.

López didn’t look as sharp or overpowering as Hicks or Crochet, but that’s no surprise either. His stuff was never quite as dominant. However, with stuff that’s more good than great, it’s fair to wonder if López can survive without diversifying his pitch mix.

He has always led with a primary fastball and a secondary slider. Still, when he was last a starter, López threw his changeup about 15% of the time. In his debut start, he used a curveball as his tertiary pitch against left-handed hitters. However, he only used two pitches against righties. That approach might not be sustainable going forward.

López is the only one of these four with previous success as a starter at the MLB level. Perhaps, then, he is the most likely to succeed this season, based on track record alone. However, he might also be on the shortest leash. I wouldn’t be shocked if the other three get a full season to work out their kinks, but the Braves aren’t going to keep running López out there if he struggles.

Thankfully for López, he certainly isn’t struggling so far.

A.J. Puk, Miami Marlins

2024 Stats2 GS, 6.0 IP, 8 R (6 ER), 8 H, 9 BB, 6 K
Pitch Mix4S (34%), SW (28.8%), SI (25.6%), SF (9%), SL (2.6%)
Average Fastball Velocity4S (93.8 mph), SI (93.6 mph)
Pitch metrics via Baseball Savant

A.J. Puk is the only reliever featured in this post who hasn’t fared well so far this season. Perhaps that’s because the Marlins’ rotation is cursed. Or, more realistically, perhaps it has something to do with just how long it’s been since he started a game.

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Hicks made his last real start in 2022, López in 2021. Crochet had never started at the big league level, but he started a handful of games in college from 2018-20. As for Puk? He’s never started a game at the big league level, not even as an opener. He hasn’t been a regular starting pitcher since his 2017 season in the minors. And, well… it shows.

Puk has been unable to pitch deep into games, going just two innings in his first start and four in his second. He has walked nine of the 35 batters he has faced while striking out just six. He has actually done a good job limiting hard contact, and opposing batters can’t maintain a .400 BABIP against him forever. Moreover, he’ll have better luck once he gets to face a lineup with a few more lefties; the southpaw has only faced one same-handed hitter so far this season.

Still, Puk needs to demonstrate better control of his pitches and at least a semblance of competence against right-handed batters if he’s going to stick in the rotation.

For what it’s worth, Puk made an effort to switch things up in his second start. He threw more fastballs, more splitters, and significantly fewer breaking balls. As a result, he was able to throw more strikes and pitch deeper into the contest. However, he also gave up more contact – and significantly harder contact.

Last year, Puk ranked among the NL’s best relievers in walk rate, strikeout rate, and hard-hit rate. Can he find a way to succeed in all three areas as a starter?

He still has time to figure things out, but if he can’t, Puk may find himself back in the bullpen when Edward Cabrera and Braxton Garrett return from the IL.

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