Diamondbacks 2024 Player Projections: Paul Sewald

The veteran closer is projected for some regression in 2024

This article is part of a series taking a look into individual Diamondbacks player projections as we head into the 2024 spring training. The projections presented are a composite of the rate (percentage) stats from Steamer and ZiPS as published on FanGraphs. The playing time projection is our own and is based on the current roster as of the time of this writing. Further roster changes will impact the playing time and thus the WAR projection, but not the rate or percentage statistics presented.

Paul Sewald was acquired from the Seattle Mariners at the 2023 trade deadline, in exchange for outfielder Dominic Canzone, and infielders Josh Rojas and Ryan Bliss. The Diamondbacks had experienced a stark deficiency in the closer department in 2023 and many seasons prior, running with an ever-disappointing closer by committee rotation. 

Once Sewald arrived in Arizona, he began to help the struggling bullpen settle into roles, and despite some stressful outings and a couple of blown saves, was very effective at getting the job done, going 13-for-15 in saves in the midst of a critical playoff push. 

Sewald certainly didn't look perfect, but provided much-needed role-defining stability to the D-backs, and his brilliant run in the playoffs was instrumental in allowing Arizona to reach the World Series.

The Projection

Alex D'Agostino

The right-handed closer is expected to see a dip in his numbers. While this might look like a severe regression at first glance, the truth is that his isolated numbers with Arizona in 2023 were a bit below his numbers with Seattle. 

Sewald is projected to see a raise in both his ERA and FIP (Fielding Independent Pitching) and a somewhat sharp decrease in his ability to strike batters out, with a nearly 6% dip in K%. He's expected to provide around half the aWAR he recorded in his previous two season totals, but both Steamer and ZiPS expect him to get a somewhat better handle on the walk problem exhibited in Arizona. 

Steamer is less optimistic about Sewald's ERA, expecting him to near 4.00, while ZiPS has more confidence in the veteran, giving him a 3.60 projection, which, according to the rest of ZiPS' projections, would have Sewald tied with Kevin Ginkel for the second-best ERA on the team, behind only Zac Gallen (3.57).

ZiPS expects Sewald to have less opportunities to pitch in 2024, giving him just 55 innings, while Steamer expects an increase in need for the late reliever, giving him a projected 66 inning workload.

Why Sewald might outperform this projection

While these numbers might not look incredibly promising, the fact is that closers need to close. When discussing overall value, plenty of intangibles get left out of the stat sheet, and Sewald brought plenty of those to the table in 2023. 

For one, can the closer close consistently? Sewald did, stressful outings aside. And the ability to slot him in the 9th inning of close games opened up their playbook to put guys like Kevin Ginkel and Ryan Thompson in more defined roles as well. The "three-headed monster" of Thompson, Ginkel and Sewald was nearly perfect in the playoffs, and that doesn't happen without a defined, veteran closer.

Sewald was 13-15 in regular season save opportunities, and he carried that into the postseason with another 6-for-7 run of saves. While many will remember the tough blown save in game one of the World Series, and his subsequent rough outing in a non-save situation in game five, the fact is that the D-backs likely don't make it nearly as far in the postseason without his efforts.

He allowed zero runs and just three hits in his first eight outings of the playoffs, including critical back-to-back saves against the Brewers in the Wild Card and Phillies in the NLCS. He had a 16/3 K/BB in the postseason.

Sewald's underlying metrics were all very impressive in 2023. He ranked in the top 5% in MLB in xERA (2.75), xBA (.189), average exit velocity (85.9), strikeout rate (32.1%), and hard-hit rate (29.9%). 

Yes, that's a lot of categories. He also ranked in the 73rd percentile in whiff rate and 83rd in barrel rate. He had an overall pitching run value of seven.

Not only are his underlying metrics good, Sewald is an incredibly clutch arm. Opponents slashed .157/.247/.253 in high leverage against him in 2023.

By most metrics, Sewald's actual 2024 numbers shouldn't even come close to his projections. Being such an excellent strikeout reliever, the 27.9% strikeout rate seems low, and he could easily surpass that, as it would be his lowest full-season K% since 2019. More strikeouts than what is expected would not be at all out of the question, and that category alone could see a significant over-performance in ERA, FIP and aWAR.

Why Sewald might underperform this projection

Those who watched every one of Sewald's outings in 2023 definitely lost a few years off their lifespan. Not to mention, the closer got off to a rocky start with the D-backs, blowing his first save opportunity in spectacular, back-to-back home run fashion.

He struggled greatly with control and throwing non-competitive pitches for a stretch of his D-backs 2023. While his overall season showed a 9.6% walk rate, it was significantly higher with the D-backs (12.5%) than it was with the Mariners (8.3%). While his issues with walks and high WHIP of 1.47 with Arizona could have come down to a stretch of overuse, he did put batters on at a concerning rate in the regular season.

Sewald's velocity was also in the bottom 30% of the league. His fastball topped out at around 92mph. And while location was his weapon, if that starts to decline, or a spot is missed badly, that baseball could end up in the next area code. 

He also showed out with an 8th percentile ground-ball rate (32.6%), and his primary manner of getting batters out came from either strikeouts or long flyouts. With Sewald facing his eighth MLB season at age 34, we could see both his velocity and location start to take a dive. If exceptional defense isn't played behind him, his numbers could easily start to sharply decline, and we could see his ERA start to climb into the 4.00's.

Sewald is also two-pitch arm. While he has been able to utilize his limited arsenal exceptionally well, his slider/sweeper is his only secondary pitch, and had a total movement of 5.6 inches below average in 2023. 

We saw that AL teams, like the Minnesota Twins and former AL West rival Texas Rangers, who were familiar with Sewald's arsenal and strategy were able to tee off on the closer, and more time in the NL could allow batters to figure him out quickly, setting him up for a regression in 2024.

Summary

What Sewald brought to the D-backs' struggling pen is much beyond the stat sheets. However, both projection systems expect him to struggle a little more in 2024. While he certainly has been an effective arm, with underlying solidity, there's also a chance he will begin to decline with age and more exposure to D-backs rival opponents. The veteran closer is a positive clubhouse presence regardless, and, barring any severe regression, will continue closing duties in 2024.

Paul Sewald Became the Closer the Diamondbacks Always Needed