Diamondbacks acquire closer Paul Sewald from Mariners: What he brings to Arizona

The Arizona Diamondbacks acquired closer Paul Sewald from the Seattle Mariners, the teams announced Monday. Here’s what you need to know:

In the deal, the Mariners receive third baseman Josh Rojas, outfielder/first baseman Dominic Canzone and shortstop prospect Ryan Bliss from the Diamondbacks.
Sewald owns a 2.93 ERA and 1.02 WHIP in 43 innings pitched this season.
The MLB trade deadline is 6 p.m. ET on Tuesday.

Diamondbacks IF Josh Rojas, OF/1B Dominic Canzone and IF Ryan Bliss going to Mariners for reliever Paul Sewald, source tells @TheAthletic. First with deal: @nickpiecoro

— Ken Rosenthal (@Ken_Rosenthal) July 31, 2023

The Athletic’s instant analysis:

What Sewald brings to Arizona

Don’t let the middling velocity lead you astray. Sewald has fantastic stuff — top 10 among relievers in Stuff+ — and 10th in strikeout rate as examples — and is a great addition to one of the worst bullpens among contenders. He does it by combining unexpected movement from a rare release point, and at this point has been successful enough not to worry too hard about the 92 mph fastball.

The one thing Sewald can’t do is clone himself, however. An Arizona bullpen that was 27th in Stuff+ and 17th in strikeout rate can’t be fixed with just one arm. Maybe the Diamondbacks will add a lower-cost rental reliever to strengthen the core behind Sewald.

At least they made this move, though. It was sorely needed, this year and next. — Sarris

Breaking down the prospects

Rojas was a 3.2 rWAR player last season in what will likely stand as his career year, but he’s careened all the way down below replacement level with a .228/.292/.296 line so far this year, including zero home runs in 59 games and his worst walk rate as a big leaguer. He’s a below-average defender at short and third, capable enough at second, and can fill in as a corner outfielder, making him a great utility player when he hits at all, which he did not just in 2022 but in 2021 as well.

His inclusion also balances out the money involved, as he makes about 2/3 of what Sewald does. Bliss is listed at 5-foot-6, 165 pounds, and I believe it, as he is definitely my height at most, but he hits the ball pretty hard for a smaller guy. His season line is completely misleading, as he spent most of it in homer-happy Amarillo and then moved up to playing on the surface of one of Jupiter’s lesser moons, known as Reno, but he’s still hit .283/.352/.455 on the road this season. I think that’s a far better indicator of his skill set — some hit, some patience, a lot of contact (17 percent strikeout rate this year), a little bit of power.

A shortstop at Auburn when the Diamondbacks took him in the second round in 2021, he’s primarily a second baseman now. He’s also a plus runner with 35 steals in 46 attempts this year.

Outfielder Canzone has taken advantage of those same hitter-friendly ballparks the last two years, but he just doesn’t swing and miss, and he’s making hard enough contact that he might turn into a solid-to-average regular in a corner, or at worst an outstanding left-handed stick in a platoon. This seems like an outstanding return for a year-plus of a good reliever. — Law

GO DEEPER

MLB Trade Grades: Diamondbacks get their closer in Mariners' Paul Sewald

Backstory

Sewald was the Mets’ 320th pick in the 2012 MLB Draft. He made his major-league debut in 2017 with New York, where he spent the first four years of his career. Sewald was non-tendered by the Mets after the 2020 season, which was shortened due to the COVID-19 pandemic, and became a free agent. He then signed a minor-league contract with the Mariners and was invited to their spring training camp.

Sewald made the Mariners’ major-league roster in May 2021, posting a 3.06 ERA and 1.02 WHIP in 64.2 innings pitched that season. He recorded a career-low 2.67 ERA and 0.77 WHIP in 64.0 innings pitched with the Mariners in 2022.

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(Photo: Steph Chambers / Getty Images)