Sweeping Success: Can Captain Jax Take Command in Twins Bullpen?

[Nick Nelson]

The Twins have lost two of their most critical relief pitchers for the early portion of the season. If Griffin Jax can live up to his ever-climbing potential, he'll play an essential role in ensuring the bullpen can hold up in the absence of Jhoan Durán and Caleb Thielbar.

Image courtesy of Brad Rempel-USA TODAY Sports

Griffin Jax is having a ridiculous spring for the Twins. That's evident when you take a glance at this overall stats – zero runs allowed on three hits with 12 strikeouts and no walks in 7 ⅔ innings – but even more so when you dive into the underlying metrics. 

It's been noticed by his teammates, his opponents, and pitch data analysts who pay attention to specific traits. Jax isn't just pitching well and getting outs; he is blowing people away. Heading into his age-29 season, the right-hander appears to be unlocking the true peak of his powers – and at an ideal time for the Twins.

Minnesota's bullpen was shaping up as a major strength heading into the season, projected by FanGraphs as the second-best unit in the majors. That was before the team received a double-whammy of bad news last week: Caleb Thielbar's balky hamstring was not improving, and worse yet, Jhoan Durán had developed a moderate oblique strain. Both will open the season on the injured list, and given the nature of these soft-tissue injuries, the Twins should probably grow accustomed to life without them for awhile.

It's expected that two relievers will primarily be leaned upon to fill this high-leverage void in the late innings. Jax and Brock Stewart were already lined to play critical setup roles, but now will factor in at the very end of games, and in the very most pivotal of moments, which usually would've gone to Durán. Stewart is capable but needs to be handled very carefully given his injury history, meaning Jax figures to elevate as Rocco Baldelli's top bullpen ace.

 

Relative to Stewart, Jax can be ridden to some extent in the absence of Durán, counted on to throw multiple innings or pitch on consecutive days. Jax has been a durable and dependable workhorse out of the bullpen after originally coming up as a starter. With that in mind, it's hard to overstate just how impactful his presence can be early in the season.

Jax owes much of his success to an evolving hard slider (or "sweeper") that is among the filthiest pitches in all of baseball. Last year in his breakdown of best pitches in MLB, Eno Sarris of The Athletic gave Jax the silver medal for sweepers (behind only Sonny Gray): "It’s a true frisbee, with nearly 14 inches of horizontal movement. What’s remarkable about this pitch is that Jax gets above-average movement, but he also throws it nearly 87 mph on average."

Jax threw his sweeper 53% of the time last year, and it held opponents to a .197 average with a .243 xwOBA. Somehow, his best pitch seems to be getting better. As Bobby Nightengale of the Star Tribune reported earlier in camp, a few Twins catchers rated it this spring as the best pitch on the staff (lofty praise given Jax's peers).

"For how hard he throws it and how much movement it has, I've never seen anything like that," non-roster catcher Patrick Winkel told Nightengale. "Usually when you see a slider, if it's really hard, it doesn't move as much. It's shorter. He throws it 90 mph and it has the movement of one that is 82 — so much movement that it's incredible."

 

Data analyst Thomas Nestico, who breaks down in-depth pitch analytics for his Patreon TJ Stats, marveled recently about how Jax's sweeper has broken his tjStuff+ model this spring, producing absurd chase and whiff rates. I reached out to Thomas for his thoughts on Jax and what makes the pitch such a weapon, and he elaborated on Winkel's insight. 

"Griffin Jax's sweeper is one of the more unique pitches in baseball," he told me. "Its combination of glove-side movement and velocity is uncommon for pitchers. Generally, sliders which are thrown at higher velocities sacrifice movement, and the same the other way around. Jax defies this conventional thought by throwing one of the hardest sliders in the league, and with enough horizontal movement to classify it as a sweeper. This spring he increased the velocity on the sweeper to 88 mph, up from 86.7 mph from last season, while maintaining horizontal movement."

 

Baldelli, who turned to Jax a team-leading 71 times in the 2023 season, obviously appreciates the featured sweeper offering. But Rocco also values the reliever for his versatility, and the depth of his arsenal as a former starter. "Griffin is a rare reliever that has five legitimate major-league pitches," he told reporters in Fort Myers on Saturday. 

This spring, Jax has been working to reintroduce a curveball into his pitch mix. As Baldelli shared, "I think he and our pitching coaches are going to identify guys where that curveball should factor in ... We’re gonna have a plan for it."

"He can spin a baseball really effectively," the manager added, "and he can do it in a lot of different ways, and most people can’t do it in that many ways."

Last year, Jax was good – much better than his 3.86 ERA, which was inflated by a few spells of poor batted-ball outcomes. He was especially good late in the year when it counted most, posting a 2.45 ERA in September and carrying that success into October where he was flat-out dominant. Jax retired 11 of the 12 batters he faced in the playoffs, including five on strikeouts.

Yet somehow, Jax still seems to be finding another gear. Driven by his curiosity as a notorious "tinkerer" and the discipline developed through a military background (Jax is a Captain in the Air Force), he keeps on improving. It's an extremely exciting prospect at a time where the Twins need him to take control as the bullpen looks to reconfigure itself mid-flight in the early weeks. 

"I don’t really see a situation where I wouldn’t wanna pitch Griff," Baldelli said on Saturday. "You wish you could pitch him and use him every game, in some way, shape or form ... He has weapons to face any type of hitter that he might run up against."

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[Karbo]

Let's hope he can carry his ST success into the regular season. With so many RP out he will be relied on probably heavier than ever.

[mikelink45]

Let's hope that for once we can rely on ST stats and that he will give us the security we need at the end of games.  If he does his story will continue to grow as we look at this Air Force arm!

[FlyingFinn]

Pretty soon he's going to be the last man standing as Topa joins the others on the IL.

[CCHOF5yearstoolate]

I think (and hope) that Rocco will use Jax as the fireman early on in the season, rather than a strict 9th inning closer.

It's quite a luxury to have Brock Stewart for that role, as his better fastball & changeup will help him deal with both sides and he seems like a pitcher who would benefit from a more structured usage vs. Jax who seems to have a rubber arm.

[jmlease1]

Jax's conversion to the bullpen has worked out pretty well. I think he's still get deployed more in the fireman role (facing heart of the order groups in the 7-9th inning) rather than be used as a 90's-style "closer" (designated 9th inning guy), at least I hope so. He's really good, and I'm glad to see him succeed.

It's impressive that his sweeper and 4-seamer are both still so effective against LH hitters, and if he can tighten up that change to torment LH hitters, he's going to have a monster year as a reliever who can be deployed against basically anyone.

[tarheeltwinsfan]

If Jax takes Duran's place, who takes Jax place?

[DJL44]

This spring is showing the importance of adding bullpen depth. Thielbar and Duran were pretty important last year and without Okert and Jackson the Twins would be relying on Headrick and Sands for innings.

[bean5302]

Though he's a righty and not a lefty, Jax's move to the bullpen reminds me a lot of what happened with Glen Perkins. Perkins didn't have great velocity as a starter, but moving him to the pen really had his stuff play way up.

[DocBauer]

6 hours ago, tarheeltwinsfan said:

If Jax takes Duran's place, who takes Jax place?

I think, more than likely, that Stewart takes Duran's role as a 1 inning closer and Jax continues in his role as a fireman in whatever  inning he's needed...occasionally the 9th I'm sure...and he can sometimes go more than a single inning, though I don't know that you want to use him that way too often right now.

It SOUNDS like Topa's injury is mild tendonitis. If that's true, and he's back in a couple of weeks, that really helps. Without him, I feel less confident in the 6th-8th innings that I did previously. I think Okert can do a solid job while temporarily filling in for Thielbar, based on his career to this point. 

Jackson has had a great ST, for what it's worth. Alcala is healthy and again and throwing hard. (Yes, he's had a couple bad games). And Funderfurk has looked pretty real going back to last year. If those 3 can be the primary 6th-7th inning guys I feel pretty good in the short term.

I can't wait to get both Duran and Thielbar back, but there's still a potentially decent pen for the short  term, especially if Topa is back and ready to go quickly. But I think Jax maintains the same role he's had before, not the closer,  but a fireman/setup arm.

[jmlease1]

2 minutes ago, DocBauer said:

I think, more than likely, that Stewart takes Duran's role as a 1 inning closer and Jax continues in his role as a fireman in whatever  inning he's needed...occasionally the 9th I'm sure...and he can sometimes go more than a single inning, though I don't know that you want to use him that way too often right now.

It SOUNDS like Topa's injury is mild tendonitis. If that's true, and he's back in a couple of weeks, that really helps. Without him, I feel less confident in the 6th-8th innings that I did previously. I think Okert can do a solid job while temporarily filling in for Thielbar, based on his career to this point. 

Jackson has had a great ST, for what it's worth. Duran is healthy and again and throwing hard. (Yes, he's had a couple bad games). And Funderfurk has looked pretty real going back to last year. If those 3 can be the primary 6th-7th inning guys I feel pretty good in the short term.

I can't wait to get both Duran and Thielbar back, but there's still a potentially decent pen for the short  term, especially if Topa is back and ready to go quickly. But I think Jax maintains the same role he's had before, not the closer,  but a fireman/setup arm.

I think you're right about Jax & Stewart's roles, which would make sense for both of them from a performance and health standpoint. 

I'm assuming you're talking about Alcala being healthy and throwing hard? I'm still a big fan of his, and if he can throw the changeup effectively enough to not get killed by LH hitters, he'll do well because he's death against righties. Stewart, Jax, Okert, Jackson, and Alcala is still the foundation of a solid bullpen and should be able to hold things down until Duran & Thielbar are back.

(It's going to be interesting to see how long it takes Duran; there are people on this board stating with certainty that he isn't going to pitch until June...)

[DocBauer]

4 minutes ago, jmlease1 said:

I think you're right about Jax & Stewart's roles, which would make sense for both of them from a performance and health standpoint. 

I'm assuming you're talking about Alcala being healthy and throwing hard? I'm still a big fan of his, and if he can throw the changeup effectively enough to not get killed by LH hitters, he'll do well because he's death against righties. Stewart, Jax, Okert, Jackson, and Alcala is still the foundation of a solid bullpen and should be able to hold things down until Duran & Thielbar are back.

(It's going to be interesting to see how long it takes Duran; there are people on this board stating with certainty that he isn't going to pitch until June...)

Thank you for the correction on Alcala. Sometimes I type faster than I think. LOL

Oblique injuries are sometimes really nasty for a pitcher. Since Duran's is listed as "moderate" I'm going to assume they will do a great job rehabbing him and he will be back ASAP and free of any other issues the rest of the year. However, when they say "up to 6 weeks" for Duran, I'm just assuming it will be 8 weeks. So yes, I could see  end of May or first of June as viable. And while I wouldn't DARE demean Duran's ability or importance in any way, if Topa and Thielbar can come back fairly soon,  and we have no additional injuries, there's enough talent  and depth to still have a decent pen for those  first couple of month,  IMO. Duran healthy and ready to go from June on is more important than rushing back, that's for sure.

[jkcarew]

How did he lose 10 games (team leading) last year, blow 7 saves (team leading) and have an overall net negative Win Probability Added?

It’s an enigma, wrapped in a riddle….

[tarheeltwinsfan]

19 hours ago, jkcarew said:

How did he lose 10 games (team leading) last year, blow 7 saves (team leading) and have an overall net negative Win Probability Added?

It’s an enigma, wrapped in a riddle….

Who are you writing about?

[jkcarew]

2 hours ago, tarheeltwinsfan said:

Who are you writing about?

Jax…the subject of the article.