TCN 2024 St. Louis Cardinals Prospect #50 – Guillermo Zuñiga

photo: Guillermo Zuniga (Brian Walton/The Cardinal Nation)

Opening The Cardinal Nation’s prospect countdown for 2024 is a 40-man roster right-hander who has the stuff to become a force in the big-league bullpen. But Guillermo Zuñiga needs to recover from injury and make some changes. FREE report!

Guillermo Zuñiga

Position: Relief pitcher
Age: 25 years old
Bats/Throws: R/R
Height/Weight: 6’5/230
Acquired: Free agent signed to a Major League contract on December 6, 2022.

Home: Cartagena, Colombia

Opened 2023: Memphis Redbirds (Triple-A)
Primary team in 2023: Memphis Redbirds (Triple-A)
Finished 2023: St. Louis Cardinals (60-day injured list)

Prior Top 50 ranking – none

Click on the above photo to be taken to Zuñiga’s player page at The Cardinal Nation, with additional biography and history information.

Link to Zuñiga’s career stats

Blake Newberry’s scouting report

Blake’s ranking – no. 49

(current grade/future grade)

FB SL CH Command Future Value
55/60 55/60 40/55 35/40 35
IP G GS ERA WHIP K% BB% HR/9 K-BB% FIP xFIP GB% BABIP
32.2 31 0 7.44 1.65 26.6% 13.0 1.65 13.6% 5.95 (AAA)

-0.74 (MLB)

 5.92 (AAA)

0.91 (MLB)

 30.0% .325 (AAA)

.500 (MLB)

There’s nothing like starting our prospect countdown with a guy who had a 7.44 ERA this past season. But, hey, there’s a reason he’s here at 50 and not 30 spots higher. If I was ranking pitchers based purely on arm talent, then Zuñiga would certainly be much higher on this list.

Alas, that is not the case. Instead, this prospect countdown begins with a pitcher whose numbers do not match the eye test. I mean, Zuñiga is flat out electric on the mound with a fastball that averages 97-98 mph and regularly reaches triple digits and is paired with an 85-89 mph slider that misses a lot of bats.

That’s a true power arsenal and it is why Zuñiga is even on this list at all after a catastrophic 2023 season. Yet something is clearly not right for the big right-hander and it’s the Cardinals job to figure out how to fix it.

The most frustrating part of Zuñiga’s season for me was that nothing changed for him. He had a rough season in Double-A in 2022 but instead of tinkering with a new pitch, a new arm slot, or different usage rates, Zuñiga largely did the same thing in 2023 and his poor results continued.

He has the kind of arm that the Cardinals and other teams should be interested in when he becomes available but he also has the kind of arm that needs tinkering if he’s going to have success.

There seem to be multiple issues with Zuñiga but there’s no bigger issue than his performance against left-handed hitters. In 2023, Zuñiga pitched well against right-handers, holding hitters to just a .637 OPS in a league with an inflated offensive environment. That number pretty much doubled when lefties came to the plate (1.271 OPS).

Guillermo Zuniga (St. Louis Cardinals)

This isn’t just a one-year trend either. In 2022, Zuñiga allowed a .547 OPS to same-sided hitters and a 1.062 OPS to opposite handed batters. He is not just worse against lefties, but downright unusable. It’s not just one area of his game that’s worse either. Zuñiga walks more lefties than he does righties, he gives up more home runs, he misses fewer bats, he gets hit more, and he gets hit harder.

Simply put, if Zuñiga only had to face right-handed hitters, he could be a key cog in the big-league bullpen right now. Factor in lefty performance and he’s a below average Triple-A arm. It makes that big of a difference.

So, what are some of the underlying issues?

The first issue I see is poor command. That’s common for flamethrowing relievers and Zuñiga is no different. While the righty walks more than his fair share of hitters, he’s also prone to missing his spots by a lot.

The problem is that I have a hard time believing it will be significantly improved. When I watch Zuñiga pitch, he looks stiff and unathletic on the mound. That’s generally not a good sign for a pitcher looking to improve his command so I really can’t project it above a future 40 grade, and even that might be a touch high.

That poor command compounds against lefties who tend to see his pitches better, which makes sense because pitchers with low arm slots tend to run larger than normal platoon splits and Zuñiga certainly qualifies as a pitcher with a low arm slot.

He’ll need to find a way around that, so this is where I think the Cardinals and Zuñiga should work on some tweaks.

The first thing I would like to see Zuñiga try is throwing more changeups. He doesn’t use the pitch all that much because he lacks feel for it at times but it did play well in limited usage. In fact, throwing the pitch almost exclusively against lefties, Zuñiga’s changeup finished the year with a 42.5% whiff rate and a 77.5 mph average exit velocity. Those are great metrics.

I need to point out the tiny sample size of just 66 pitches (10.5% usage) but the pitch does have the potential to be a lefty neutralizer. On average, it generates 17.1 inches of run, which makes me think that it will continue to miss bats even if it doesn’t have fantastic depth. With that said, the pitch has enough depth to provide about 13 inches of vertical separation off his fastball and provides enough of a velocity difference (about 8 mph) to profile as an effective pitch overall.

Here’s that changeup working away from a lefty:

He really needs to throw that thing a ton and try to improve his feel for it.

If Zuñiga can’t develop the changeup, I think he could throw a good cutter. In fact, I would probably even have him tinker with that while he’s throwing a bunch of changeups to see which pitch he likes better. Ideally, the pitch would sit right around 0 inches of horizontal break to split the difference between his four-seamer (9 inches of run) and his slider (5 inches of sweep) and would be thrown hard, in the low-to-mid 90s.

Basically, it’s just some kind of platoon-neutral gyro offering that he can use against lefties. Given Zuñiga’s arm talent, I don’t think it would be too difficult for him to develop a cutter that grades out as an above average pitch. It’s just a matter of how much feel he can develop.

That’s what I would do with Zuñiga. If neither of those things work, who cares? He’s coming off a 7.44 ERA season so he can’t just keep doing the same thing.

I don’t want to stop there, though, because there are other parts of Zuñiga’s game that need to be evaluated.

His fastball is a plus pitch simply due to its elite velocity, but I do think his fastball could stand to improve its shape as it has below average ride and spin efficiency and was hit hard this past season (93.8 mph average exit velocity).

It can be hard to change fastball shape, though, so there’s something else I would like to see him try – throwing his fastball up in the zone. This looks like something Zuñiga tries to do, though not enough, but at times, he simply isn’t great at getting the pitch up there and often misses low or in the middle third.

Even though he doesn’t have the typical fastball shape for the top of the zone, he does throw from a low arm slot, which generally helps fastballs play better up high. That’s a minor tweak that he could make that really wouldn’t take much effort. It’s simply a change in intent and philosophy.

I would also be curious to see what a Zuñiga sinker would look like because he gets above average run on his four-seamer (9.4 inches) and that’s a good sinker trait. A sinker could also help him keep the ball on the ground more and perhaps manage contact a bit better.

Finally, I should also mention the slider because it’s Zuñiga’s out pitch. The breaking ball spins at a high rate, typically around 2600 rpm, and is thrown hard, averaging 86.4 mph. Both factors help it get good two-plane movement and miss a lot of bats.

It does seem to be a little inconsistent, at times getting hard sharp break and at other times flashing a hump that makes it more identifiable. I would love to see the sharper version more often but the pitch still grades comfortably as a plus offering either way.

Here’s an example of a loopier slider:

And here’s a sharp one:

Here’s a few more for good measure, this time from Zuñiga’s World Baseball Classic stint:

I will freely admit that location likely plays a part here, but the pitch simply looks nastier when Zuñiga keeps it at the knees or below instead of spinning it further up in the zone. It’s still his best pitch for now, though his fastball has the chance to overtake it if he can fix its shape.

Overall, from a pure stuff perspective, it’s a good three pitch mix that can still improve but has a really high ceiling due to Zuñiga’s ability to generate velocity and spin. That’s why I see Zuñiga as a prospect worth paying attention to despite his poor numbers.

So, to summarize, the four developments I would like to see are more changeup usage, a new cutter, high fastballs, and some sinker tinkering, but there could be other tweaks as well. The current form of Zuñiga isn’t good enough to even be an average Triple-A pitcher, but the arm talent is that of a good MLB reliever so it’s up to the Cardinals to find out how to get him there.

Summary: Zuñiga has some of the best pure stuff in the Cardinals system, but a variety of issues have prevented him from having any kind of success against left-handed hitters. That makes him a high variance prospect and his ability to supplement his arsenal with a lefty-neutralizer (whether it be his changeup or a cutter) will determine whether he lands closer to his ceiling or his floor.

Future Value: 35
Role: AAAA player/middle relief
Risk: High

Brian Walton’s environmental impact report

Brian’s ranking – no. 51

Background

Prior to becoming a Cardinal, Zuñiga split six years in the minor leagues between two organizations with good developmental reputations – the Atlanta Braves and Los Angeles Dodgers.

Zuñiga opened his career as July 2nd signee of the Braves in 2016 but was awarded free agency following the 2017 season while still in rookie ball. He was one of 12 Braves players made free agents by Major League Baseball as part of the punishments doled out to Atlanta for numerous signing rules violations in the international market.

Zuñiga signed with the Dodgers for $200,000 heading into 2018 and spent the next five years in their system, before reaching minor league free agency following the 2022 season.

In his final year in the LA system, Zuñiga pitched for Double-A Tulsa, ranking among Texas League leaders in games (48, second) and saves (11, tie for third). In 2022, Zuñiga walked a career-high 4.94 batters per nine innings, up from 3.31 during his first Double-A season. In the same time frame, his strikeout rate fell from 12.48 to 10.87 per nine. His 2022 FIP was 5.95, though he did convert 11 of 12 save opportunities presented to him.

Over the 2021-22 seasons with Tulsa, he went a combined 11-6 with a 4.10 ERA (90.0 IP) and 115 strikeouts in 73 relief appearances.

During Zuñiga’s pre-Cardinals career, the right-hander appeared in 131 games (13 starts), recorded a 10.3 strikeout/9 IP ratio, and converted 20 saves.

Guillermo Zuniga (Tulsa Drillers)

After Zuñiga reached minor league free agency, he briefly pitched in winter ball in his native Colombia. The Cardinals quickly jumped on him, signing him in early December 2022. What was highly unusual is that he was immediately given a 40-man roster spot, something the organization that knew him the best, the Dodgers, never did. That 40-man offer may have been what sealed the deal.

The Cardinals certainly did not make their decision in a vacuum. They must have had ample opportunity to scout Zuñiga as Double-A Springfield and Tulsa play in the same division of the Texas League. Clearly, they thought they could unlock him, but as Blake explained so thoroughly, there were little to no signs of progress in 2023.

2023 recap

Zuñiga’s first year as a Cardinal was a checkered one, to say the least.

As a member of the 40-man roster, Zuñiga was invited to his first Cardinals spring training camp. However, his commitment to pitch for Colombia in the World Baseball Classic meant he entirely missed out on a most important opportunity for the Cardinals coaches to familiarize themselves with him and perhaps begin work on necessary adjustments in the lower-risk environment provided by spring training.

On the positive side, Zuñiga received rave reviews for his WBC work for Team Colombia, including throwing 102 mph fastballs past Randy Arozarena of Mexico and fanning Mike Trout and Paul Goldschmidt of the USA. In total, the right-hander struck out six hitters in three innings and allowed only two base runners, on a hit and a walk.

Colombia did not make it to the quarterfinals, as USA eliminated them from Pool C on March 15. Yet, Zuñiga did not return to Cardinals big-league camp because he had already been optioned out on March 4 while still away. As a result, he did not throw in a single game for St. Louis at any point in the spring.

How big of a contributor missing St. Louis’ camp entirely was to Zuñiga’s disappointing 2023 season is unknown, but there is no way it could have helped a minor league pitcher who was brand new to the organization.

He opened the regular season in the Memphis bullpen. By May 2 when called up to St. Louis to replace Zack Thompson, Zuñiga had a 5.40 ERA, a 9/2 strikeout to walk count over 8 1/3 innings and led the Redbirds with three saves in five opportunities. In his MLB debut stint, he made just one appearance, a 1-2-3 inning including two strikeouts, before being sent down four days later in favor of Adam Wainwright.

On June 24, Zuñiga was placed on Memphis’ injured list, and he went on to miss the next month. At that point, his five saves (in seven chances) led the team, but his ERA was 7.32 in 21 appearances totaling 19 2/3 innings. One problem was four home runs allowed. Another was 13 walks issued.

Zuñiga was activated on July 25 and continued to struggle. His ERA was up to 7.85 over 28 outings with the Redbirds when he made another short cameo of two days with St. Louis from August 19-21. This time, he allowed one run in his one inning with the Cardinals.

Four days later, he was recalled once again when Drew VerHagen went on paternity leave. However, Zuñiga did not throw a pitch this time up, as he almost immediately (August 27) went on the injured list due to a right forearm strain. Initially, he was on St. Louis’ 15-day IL, but was later moved to the 60-day, from where he ended the season.

2024 outlook

Too often it seems, a forearm strain now becomes a red flag indicator for Tommy John surgery later. However, I readily admit that I have no insight as to if this applies to Zuñiga’s current situation. I do believe that actions speak louder than words, and the actions to date are in his favor.

Since the end of the 2023 season, the Cardinals relatively quickly and explicitly pruned seven pitchers from their 40-man roster (over and above those eligible for free agency). They include Jacob Barnes, Kyle Leahy, Packy Naughton, Connor Thomas, Jake Woodford, Dakota Hudson and Wilking Rodriguez. The latter is another hard thrower with potential whose 2023 was also ruined by injury.

My reading is that Zuñiga would have been among the pitchers who lost their roster spot if the Cardinals didn’t think he could contribute at the big-league level in 2024.

Having said that, it isn’t even spring training yet and there could easily be more twists and turns ahead.

While there look to be jobs in the St. Louis pen to be claimed, it is difficult to see how Zuñiga could be fully ready to compete at that level for Opening Day. We have no idea if/when Zuñiga will be able to get enough repetition to become more than a guy known for triple-digit heat and evolve into the more complete and effective pitcher hoped for.

A year that begins back in Memphis with more chances to help St. Louis during the season when his results warrant seems his most likely 2024 scenario.

Future outlook

With Zuñiga having two more option years remaining (including 2024 potentially), the Cardinals have considerable time flexibility to invest further in him. As long as progress is being made, Zuñiga should be able to remain in the picture long enough to earn his way into becoming a regular MLB contributor.

What remains unknown is if he can and will make the necessary changes.

However, if he joins Rodriguez, Naughton and the others on the outright path, the writing as to his future would be on the wall for all to see.

If we knew the answer to this, Zuñiga would either be unranked entirely or a top 25 or 30 prospect in the Cardinals system. Stay tuned!

MLB debut: 2023
Rule 5 eligible: not applicable
Minor league options remaining: 2

Exclusively for members of The Cardinal Nation

Coach Eric Peterson on Cardinals Pitchers in the 2023 Arizona Fall League

Our 2024 Top 50 series continues

To see the entire list of top Cardinals prospects, grading scales and remaining article schedule, click here. This includes the Top 50 countdown and 12 in-depth, follow-up articles breaking down the list.

50 Days, 50 Nights, 50 St. Louis Cardinals Prospects for 2024

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