Diamondbacks Add Still-Excellent Joakim Soria to Bullpen

I’m not sure many people expected Joakim Soria to stick around this long. Perhaps that’s the case with any reliever, given how volatile they can be, and how they begin their careers with the inherent flaw of not being starters. Maybe it’s the case for all players in general — how many of today’s prospects would you bet on lasting 14 years in the majors? Careers that stretch into a player’s late-30s are rare across the board, and any player still putting on a uniform 20 years after he was signed for the first time has accomplished something impressive. But it feels especially pertinent to point out in the case of Soria, who began his big league career as a Rule 5 draft pick with a low-90s fastball only to be asked to close games as a rookie. Since then, he’s become one of baseball’s pillars of consistency. And on Wednesday, it was announced that he would be joining the eighth team of his career.

The Arizona Diamondbacks, whose offseason additions prior to this week consisted of just two minor league deals given to 30-and-older relievers, signed Soria to a one-year contract worth $3.5 million, with the potential to add $500,000 more if he hits certain innings incentives:

Soria spent 2020 as one of the best relievers in one of the majors’ best bullpens. In 22.1 innings with the Athletics, he held a 2.82 ERA and 2.97 FIP, striking out 24 batters while issuing 10 free passes (three of which were intentional). That was Soria’s third time in the last four years finishing with a sub-3.00 FIP. Among active pitchers, he’s one of the 10 best relievers in that time span.

Top Major League Relievers, 2017-20
Aroldis Chapman 180 170.1 14.21 4.17 0.53 2.64 2.35 2.85 5.7
Roberto Osuna 174 171.1 10.03 1.31 0.63 2.84 2.46 3.21 5.8
Liam Hendriks 184 187.2 12.09 2.49 0.77 2.83 2.47 3.28 6.0
Kirby Yates 193 184.2 13.99 2.58 1.02 2.63 2.62 2.75 5.5
Chad Green 163 218.0 12.06 2.06 0.99 2.77 2.71 3.17 5.5
Ken Giles 175 169.2 11.94 2.60 0.90 3.02 2.73 3.08 4.2
Joakim Soria 217 207.0 10.43 2.87 0.61 3.61 2.78 3.67 5.1
Tommy Kahnle 166 148.1 13.17 3.22 0.97 3.64 2.81 2.85 3.4
Josh Hader 172 223.2 15.29 3.30 1.25 2.54 2.85 2.66 6.2
Brad Hand 224 230.2 12.60 2.73 0.90 2.61 2.87 3.14 5.5
Active pitchers, minimum 100 innings

Soria isn’t at the top of this list, but he does stand out because of his age. While several of his contemporaries hover within a few years of 30 — or, in the case of Hader and Osuna, are still several years away — Soria will turn 37 in May. Depending on what your definition of elite is, he’s either above that mark or very close to it, despite pitching through ages when many of his peers experience a sharp decline. Even more impressive is how close a resemblance this four-year span of time bears to the rest of his career. You can’t break down 13 seasons evenly, so here is Soria’s career split into three-season chunks, with the exception of the final stretch, which includes the partial 2020 season:

Joakim Soria’s Career in Four Parts
Seasons IP K/9 BB/9 HR/9 ERA FIP xFIP WAR
2007-09 189.1 9.98 2.57 0.62 2.09 2.83 3.26 5.1
2010-13 149.2 9.56 2.83 0.78 3.01 3.10 3.18 3.0
2014-16 178.2 9.07 2.62 1.01 3.27 3.55 3.46 2.1
2017-20 208.0 10.47 2.86 0.65 3.63 2.83 3.66 5.1

Depending on how much you care about luck as opposed to real results, Soria’s last few seasons are either a little better or a little worse than the rest of his career. Even everything out, though, and he’s been a remarkably similar pitcher year to year, particularly if you compare the first three years with the last four.

Soria was one of baseball’s best closers in his very first season, and he held that distinction for four years. He had dominant half-seasons with the Rangers in 2014 and the Pirates in ’15 before rejoining the Royals, for whom he was again exceptional in ’17. He’s finished six of his 13 major league seasons with a FIP under 2.75. Maybe a large portion of the baseball-watching public is made up of Soria stans and I’ve just missed it — I am a younger guy who grew up watching NL teams, after all — but I get the impression he isn’t appreciated as much he probably should be. Relievers are supposed to be unpredictable, volatile power arms without much room for error when things start to go south. And yet, Soria has never provided reason for concern. He’s been a consistent late-inning force year after year, while making minimal tweaks to his arsenal.

Over the years, Soria has changed his No. 2 offering — at various times, it has been a cutter, changeup or slider — and how often he throws it. What’s remained consistent, though, is his four-seam fastball. That’s always been his primary pitch, and he’s relied on it even more of late. His three highest fastball rates of his career have all come in the past three years. That’s a bit surprising — though he hasn’t lost any meaningful velocity in his mid-30s, he also hasn’t picked any up. His fastball still rests in the low-90s, hardly in line with the power arms usually entering late in games. But Soria’s fastball works. Over the last three seasons, hitters have managed just a .301 wOBA against it. And that’s the pitch batters are hoping for a chance at, because their chances drop even further against Soria’s breaking stuff.

Soria’s slider and curveball both have vertical breaks in the 94th percentile or better, and they appropriately get a lot of whiffs. And yet, he’s throwing them less than a quarter of the time. That’s not a criticism, given how much success Soria already has. But it is worth pointing out that because those pitches move so much, and because he has an ability to throw both for strikes, he has some considerable room to up their usage and give himself some wiggle room whenever the day comes that his fastball velocity does begin to dip.

If you’re a Diamondbacks fan looking for a reason to be concerned, there are areas to nitpick. Soria just posted his highest walk rate since 2013, and his lowest strikeout rate since 2016. His strike rate was the lowest of his career. His GB/FB ratio also plummeted to 0.53 in 2020, down from a career average of 1.17, and his rate of homers per fly ball was extremely low. Before last year, Soria had never posted an xFIP above 3.91 — in 2020, it was 5.15. All of that information bunched together sounds scary, and yet, Soria’s xwOBA and xERA still ranked in the 92nd percentile, his best showings of the Statcast era. He’s just a very good, consistent pitcher who’s still capable of finishing games.

That’s likely what Arizona will ask him to do, given the lack of experience throughout the rest of its bullpen. The other eight pitchers on the roster projected by Depth Charts to throw at least 30 innings in relief have made a total of 239 major league appearances — fewer than 30 per pitcher. Soria has thrown 732 big league games by himself. Yes, there’s the popular refrain that bad teams don’t need closers, and while I’m not sure the Diamondbacks are bad, I certainly wouldn’t call them good. But every team needs pitchers it can place in positions to succeed, and I’m still skeptical that the Diamondbacks have enough of those. Soria will be a stabilizing presence late in games, and he’ll probably bring back a couple of minor leaguers in July. That isn’t a bad investment at $3.5 million, and with a long list of relievers still unsigned, it’s the kind of investment any team can still make.

Tony is a contributor for FanGraphs. He began writing for Red Reporter in 2016, and has also covered prep sports for the Times West Virginian and college sports for Ohio University's The Post. He can be found on Twitter at @_TonyWolfe_.

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RE: Top Major League Relievers, 2017-20

Using FIP or FIP- Soria does end up pretty high on the list — but xFIP/xFIP- have him much further down thanks to his really low HR/FB%.

Right from the Fangraphs page on the subject it seems to be a factor considered to be heavily influenced by luck and otherwise in Soria’s career, he’s been closer to average in this regard.

2007-2016 he had a 3 point spread in FIP- to xFIP- (compared to the 19 point spread for the 4 seasons covered in the table). If he hasn’t added a HR/FB%-reducing skill in the last few years, might the table in the write-up be overstating him a bit?


Just to build on that thought– Soria had the 19 point gap in FIP- and xFIP- for 2017-2020 while being roughly even (-2) 2013-2016.

I picked 2010-2013 largely at random and grabbed the list of RPs who had a gap of >=12 points (n=18), min 120 IP. And then pared the list down based on the previous four years– +/-6 point range (and also 120IP):

59 63 64 76 -5 -13 Mariano Rivera
78 84 81 96 -3 -12 Rafael Soriano
78 70 84 84 -6 -14 Brian Wilson
92 76 94 89 -2 -13 Jesse Crain
88 64 86 83 +2 -19 Joakim Soria

Just to start with–Soria is already far more extreme than the “comps”, both in terms of the gap in the later period and the spread between that gap and the gap from the previous period.

But to the burning question– how did those four fare the next year?
Well, Rivera bones us by retiring while he seemed like he could have continued being an above average RP for several more years. Jesse Crain had some sort of injury and never pitched in the Majors again (and even only 5 total innings in the minors)

Soriano’s FIP- dipped only slightly to 84, but his xFIP ballooned to 106. Brian Wilson had FIP- and xFIP- of 115+