Daysbel Hernández could be the closer of the future for the Atlanta Braves

The big Cuban righty has electric stuff and is learning on the job

It’s really hard to claim that a Cuban baseball player doesn’t have the mental toughness required to be a closer.

After all, they had to leave their home country in a perilous journey, often leaving their families behind, just to have a chance in the Major Leagues. While there’s the omnipresent promise of money ahead of them should everything go right, they’re defecting to secure a better life for themselves and out of a passion to play the game at the highest level.

Daysbel Hernández isn’t any different - defecting in 2017, the Braves discovered him in Florida at a tryout and gave him a minor league deal that September. He steadily moved up through the minor league system, taking a lengthy pause for the lost 2020 season and again after needing Tommy John in early 2022, finally debuting in late 2023 for Atlanta.

After two seasons spent moving up and down between Atlanta and Gwinnett, Hernández is one of the best-performing arms for the Braves, holding a reliever-best 2.16 ERA (among relievers with 10 or more innings on the season).

Let’s talk about it.

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What he does well

Gas.

Daysbel’s average fastball velocity is 97.6 mph, establishing him as not only the hardest thrower on the active roster but one of baseball’s hardest-throwing relievers with a 94th percentile mark in that regard.

Since his debut in 2023, here’s the number of 99 mph+ fastballs thrown by every single Braves pitcher:

Spencer Strider: 87 (all but one in 2023)
Daysbel Hernández: 15
AJ Smith-Shawver: 2
Reynaldo López: 1

The hardest pitch of 2025 and of 2024 both belong to Daysbel, touching 99.6 this year (April 26 vs Gabriel Moreno) and 99.6 last year (Nick Senzel on June 8th).¹

But here’s the thing: Daysbel doesn’t act like that fastball’s his best pitch. He throws it just 41% of the time.

Because his slider is AWESOME.

Coming in at 88.3 mph and with above-average drop from a high three-quarters slot, it’s a legitimate weapon that is the 2nd-most heavily used out of the entire bullpen, behind only Pierce Johnson’s 69.3% usage of his curveball.

And when it’s on, it’s unhittable.

Here’s one that put away Tyler Stephenson of the Reds on Tuesday:

The movement, the location - just sublime.

It’s powered him to the best ERA in the bullpen.

But he’s also gotten a bit lucky to this point of the season so far, as last night’s game illustrated.

He’s overperforming the inputs

Daysbel Hernandez’s ascension to 8th inning duties was a long time coming for the Braves, but he’s looked so comfortable in the role because he’s also gotten a bit of good luck on his batted balls. Entering Tuesday’s game, the difference between his actual ERA (1.72) and his expected (2.66) was almost a full run, fueled by some hard-hit balls that have been caught for outs. His actual slug was 150 points better than the expected mark of .310, which still isn’t bad but was almost double of the actual .160 mark.

(For context on how bad a .160 slug is, Tuesday night’s analyst on the broadcast, Tom Glavine, had a career .210 slug across his 22-year career. And because they competed at everything, Greg Maddux had a .205 and John Smoltz had a .207.)

We saw some of this luck normalize - he hung a slider to Santiago Espinal that was hit for an RBI single in the 8th inning, just four pitches after striking out Stephenson.

It’s just the fifth hit Daysbel’s allowed on forty-two sliders in the middle or top third of the zone this season. And there’s some good hitters that haven’t done much with that pitch - Shohei Ohtani flew out to right, Mookie Betts flew out to right twice, and both Nick Castellanos and J.T. Realmuto grounded out on the same pitch.

Those batting average and slugging numbers are still the largest overperformance over the expected numbers of any qualified pitcher on the team, even accounting for last night’s run. Daysbel is currently benefiting from 61 points of batting average overperformance and 129 points of slugging overperformance - the next closest Braves are Dylan Lee’s 51 points of batting average and Enyel De Los Santos’ 107 points of slug.

For relievers, sometimes this doesn’t normalize over a full season, owing to the small samples.

But for Daysbel, there’s hope that he can keep this performance up owing to the exceptional ‘stuff’ on both the slider and the fastball, combined with his velocity.

Training to be the closer?

Raisel Iglesias is a free agent after this season. Despite not having the start to his season that he wanted, he’ll still be in demand as one of the best closers in a free agent class that features some big names at the top (Devin Williams, Ryan Helsley, Edwin Díaz if he opts out) but quickly falls off to flawed set-up options like Ryan Pressley, Liam Hendriks, and Michael Kopech.

Is it possible that the Braves re-sign him? Of course it is.

But if they don’t, Daysbel’s next in line to get the opportunity.

In his major league career, he’s holding a 2.64 ERA in non-save situations and a 2.70 in save situations, albeit with the caveat that he’s been thrust into that save situation exactly seven times in 36 career games.

In his AAA career, he’s had 34 plate appearances in the 8th, 9th, or extra innings where the tying or go-ahead run was either on base or at the plate. He’s given up exactly seven hits, all singles, and walked just three batters while striking out nine.

Of the 96 plate appearances classified as save situations on Baseball Reference entering Wednesday’s action, Daysbel’s third on the team with 20, behind just Dylan Lee (27) and the actual closer, Raisel Iglesias (31). Daysbel’s allowed a .125/.300/.188 line in those situations, second only to Pierce Johnson’s .111/.200/.111 in 10 plate appearances.

But Daysbel’s also issued four of Atlanta’s nine walks in those situations, more than double anyone else. And there’s the rub.

The walks need to come down

The only reliever to pick up 25 or more saves last year with a higher walk rate than Daysbel’s career 4.7 BB/9 was Alexis Díaz’s 5.0. If you expand that to 20 or more saves, you add two more names: Craig Kimbrel (5.3 BB/9) and Camilo Doval (5.9 BB/9).

Not the company you want to be in: Doval was optioned to the minors in August of last year, while Kimbrel was DFA’d by a playoff team in September and Díaz was optioned to the minors just last week.

And the walk rate’s already improved a bit this year, albeit with a corresponding decrease in his strikeout rate as well. After a 13.5% rate last year, which comes out to a 5.0 BB/9, his walk rate has shrunk to just 11.3% this year. The problem is, his strikeout rate’s also made a corresponding drop, going from 35.1% to a relatively pedestrian 19.4%.

Again, small sample size caveats apply - he threw just 18 innings last year and 16.2 this year. It’s hard to determine what is an actual signal of growth and development and what is noise at the moment.

But with Iglesias potentially departing in free agency this offseason, we’ll give an homage to Star Wars with this: We will watch your career with great interest, Daysbel.

Because you might be the Chosen One.

1. The only regular-season pitches a Braves player has thrown in three seasons that broke 100 are Spencer Strider’s fastballs back in 2023, doing it three times in the same at-bat against Eloy Jiménez on July 15th and then again to Zach Neto on August 1st and Mookie Betts on August 31st.