The Diamondbacks had an absolutely abysmal season in 2021. They weren’t exactly expecting to be world-beaters, and they had a tall order competing in a division that had two huge pre-season favorites in the Dodgers and Padres as well as the Giants who ended up putting together an incredible year. They do have some talented players, but a lack of depth and lack of overall quality doomed them to lose an embarrassing 110 games. 

Heading into the season, their big bullpen additions were Joakim Soria and Tyler Clippard. They went into the season having tabbed Stefan Chrichton as their closer, with Soria, Clippard, and fireballing Kevin Ginkel in line for other high leverage work. Obviously the bullpen wasn’t the only thing that went wrong for Arizona in 2021, but it was a pretty terrible area for them all around. 

Only seven of the 26 pitchers who made more than 8 relief appearances for the Snakes managed to put up a positive WAR value, which is very bad. They had six pitchers who logged more than 25 appearances and still put up negative WAR totals, and a team is never going to do well when they are utilizing worse-than-replacement quality pitchers for such a significant number of innings. 

Of the four top relievers going into the season, only Soria managed to generate positive WAR, albeit only 0.2 worth. Stefan Chrichton was supposed to be the closer but he found himself pitching in Reno by the time August rolled around. Same for Ginkel. Soria was traded at the deadline, and Clippard underperformed, his 3.20 ERA not quite doing enough to hide his poor underlying stats and sub-0 WAR. 

By the end of 2021, the most trusted group of relievers in the Arizona bullpen was Noe Ramierez, Taylor Clarke, and Joe Mantiply. The trio combined to cover 118.2 innings and each hurler posted up at least 0.5 WAR. While all three were reasonably consistent and serviceable, that is about the nicest thing we could say about them. These are three pitchers that you’d much prefer holding down the bottom few spots in your bullpen and not the three highest leverage roles. While their results were decent, there is some concern as to whether their results are repeatable. All three had unsustainably low HR/FB ratios, suggesting a decent amount of luck. While these pitchers could certainly take strides forward in 2022, there is plenty of concern that they won’t even be able to replicate their 2021 success. Noe Ramierez in particular, while his 2.76 ERA, 22% K rate and 8.3% BB rate all appear solid on the surface, a microscopic .184 BABIP and 4.3% HR/FB ratio led to a 3.48 FIP and 5.22 xFIP which is likely the range that he will be in moving forward without a significant change/increase in his overall skills. 

Fortunately for Diamondbacks fans, the news is not all bad. While teams in the midst of re-building in tough divisions typically don’t invest in the back end of their bullpen, Arizona surprisingly inked one of the top closers on the market in Mark Melancon. Melancon signed a 2-year deal with a mutual option for 2024 that guarantees him a minimum total of $8.2M, showing that Arizona wants to make an effort to stabilize their bullpen. Melancon has been one of the most consistent closers in baseball for the past two seasons. While he has never been a strikeout machine, his control and consistency have produced some stellar results and an All Star selection in 2021. While he will not strike fear into the hearts of batters like Josh Hader, in spite of the fact that he is getting on in years all signs point to him quietly continuing to provide excellent run suppression and being a guy that you feel great about handing the ball to when you need to polish off a victory. 

The addition of Melancon helps the entire bullpen. He will absolutely begin the season as the closer and almost certainly will stay there for the duration of the season barring injury. It would take a catastrophic drop-off in performance to make the Diamondbacks even consider a change, and since that seems quite unlikely, this means that the rest of the Arizona relief corps will be able to pitch in roles at least somewhat better suited to their skills, ideally allowing them to excel. What the Diamondbacks lack in quality, they make up for in quantity. They have a number of young, raw arms who will compete for the remaining spots in the bullpen, and while plenty of churn is to be expected, there is hope that some of them will take steps forwards and rise to the top. Ramierez, Clarke, and Mantiply will likely have the inside track on the other high leverage roles, but should they falter, J.B. Bukauskas, Humberto Mejia, and Sean Poppen will be waiting in the wings to pounce. 

Sean Poppen in particular is one of the most intriguing candidates to make the jump to being a trusted high-leverage arm. The Harvard-educated hurler sports some impressive credentials in his education background as well as some impressive underlying statistics that suggest the potential for success. Poppen led all Diamondbacks relievers in 2021 with a 25.6% K rate, and while his 5.16 ERA is unsightly, his FIP was a full run-and-a-half better. A whopping 4.14 BABIP suggests that he was extremely unlucky on batted balls, further evidenced by a solid 34.7% hard contact rate. His SIERA of 3.62 feels a lot more like the real-life results we can expect in the future, and while that might not land him a high-leverage role on a more competitive team, the door could well be open for him to earn an opportunity to set Melancon up assuming his real life results trend towards expectation. One would think that his advanced education would help him to make the most of his raw skills, and since he is out of minor league options, he most likely will be given the runway to find out if he can put it all together. 

Expectations for the Diamondbacks as a whole are pretty low heading into 2022. The only thing keeping them from being a near-lock to hold down the basement slot in the AL West again is the Rockies’ ineptitude. They certainly have an uphill climb before they’re going to seriously compete with the Dodgers, Giants, and Padres. While the bar is pretty low, the bullpen should be significantly improved by the addition of Melancon, and at the very least it seems that it will be other areas of weakness that cause the team’s demise instead of the disappointing effort from the relief corps in 2021.